hole in air line bricking my O2 sensors?

1998 Taurus Wagon SE, 140k miles

Error Codes:
P0135 - O2 Sensor Heater Circuit (Bank 1 Sensor 1)
P0155 - O2 Sensor Heater Circuit (Bank 2 Sensor 1)
P1131 - P11XX Manufacturer Controlled Fuel and Air Metering (aka mass air flow sensor)

Over the weekend I ultimately had all 5 of my O2 sensors replaced because the mechanic could not figure out what was triggering the two O2 sensor codes (I think he literally forgot about the third code...) I had this done out of state and on the drive back home (150 miles) my check engine light came back on. I had the error codes read again and the same 3 codes popped up again. I then discovered that I had a hole in one of the air lines and was told that that was what was causing the problem with the sensors. I replaced the hose and disconnected the battery. The engine light stayed unlit for about 20 miles but then came back on. Took it to have the errors read again and the same 3 sensors were giving errors again.

Here is my question. Is it REALLY possible that after about 150 miles worth of driving with brand new sensors (minus the mass air flow sensor), for said sensors to go bad as a result of the hole in the air line? I have a second set of sensors ready to be installed (by me this time), but I am not confident that the new ones were ruined by the hole in the line alone. My car is in fine shape all around and has had all of it's appropriate tune-ups, etc.

Thank you in advance, I'm a novice at car repair, but I'm learning.

Specifically what air line had the hole? Have you replaced the MAF sensor? The table of codes I have indicates a P1131 is "upstream oxygen sensor for bank 1 is staying lean," a condition consistent with too much unmetered air entering the engine. Not knowing more about what's going on and been done, I wouldn't replace the MAF yet. I'd be looking for a vacuum leak, hissing, cracked hoses and boots. I'm not aware of a problem from O2s with lean conditions, but have heard plenty say too rich for too long will ruin or plug them, though some have had success cleaning them. Maybe someone like Rod will set me straight on this, but I haven't heard of having five O2s, just up to four, on cars.

Thank you (exhausted?) tripletdaddy.

I'm trying to find a diagram that lables the lines so I can tell you...

I have not replaced the MAF sensor yet. There is another line that is slightly cracked on the ends, I'll replace that after work today because I have some hose left over. I'm also going to look into cleaning the sensors, know of any good tricks?

BY THE WAY

My taurus is a V6 3.0L DOHC

and I've been told that the air is too rich, never heard "lean"

and I recently got new spark plugs

Maybe someone like Rod will set me straight on this, but I haven't heard of having five O2s, just up to four, on cars.

No need to set you straight, an OBD-II car will have either 3 or 4 O2 sensors, but not five.

I also agree that the codes would seem to indicate that there is unmetered air entering the system. Since it is unmetered air, that would indicate the air leak is post-MAF sensor. I would not suggest replacing the MAF at this point, but rather closely inspecting all vacuum hoses. I don't think intake manifold gaskets are generally an issue with the DOHC, but would be worth checking as well. The "throttle body cleaner trick" would be helpful for that one.

-Rod

As a matter of fact, yes, all the time. I have three 7.5 year old BOYS!?! They are a force to be reckoned with. Thanks for noticing.

Rich and lean refers to the amount of fuel not air, which would be consistent with a lean condition and suspected vacuum hose leaks. Sure, you could say things in terms of too much or too little air, but be sure everyone will know that's what you mean.

Just for clarity, Rod, do you mean he should use the tb cleaner trick for leak detection? And, would it be worth cleaning the MAF for this problem, or is it not likely the cause?

Yep, I mean to use the TB cleaner to check for a leak. One could also use carb and choke cleaner, propane, etc. Just be very aware of what's hot under the engine since these sprays/gases are very flammable. Personally I prefer to use the sense of hearing to try to find the vacuum leaks rather than flammable liquids, but the liquids are quite effective.

It never hurts to carefully clean the MAF sensor, but since this code is for unmetered air entering the engine, I would expect the leak to be after the MAF. I suppose though if the MAF is really dirty and therefore not registering all the air accurately that is flowing through it, it may detect a lean condition as unmetered air. What I usually experience with a dirty MAF is poor fuel economy which would be consistent with a rich condition rather than lean.

-Rod

Oh snap, I forgot I posted on this forum... How about an update?

I have not resolved my problems yet, but I need to soon, here is what I've been up to:

I replaced another hose that did not look great. I had my girlfriend plug up the exhaust pipes while I listed for hissing, but did not hear anything obvious (it would have had to be REALLY obvious for me to notice it over the roar of the engine, me thinks...). I sprayed what I thought I could spray with WD40 to see if if any would get sucked into the engine and cause it to sputter: nope. I bought a MAF cleaner in a spray can, and cleaned the MAF sensor, though I must say that it looked fine to begin with, everything looked clean and dry (though I wiped everything down with a dry cloth, without touching the sensor of course). I hosed down everything under the hood, battery corrosion had gotten on a few things. I unplugged the batter for a while so that the engine light turned off, but it came on again the next day. I bought a really neat scan tool (LINK (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=98614)) which does a bunch of things, I'll post the kind of summary data that it collected below, but I also had it do a live record under city and highway conditions (it's a LOT of data). Next I'm going to clear the codes with the scan tool and try everything again.
Control Module
$10 SAE J1850 PWM
Vehicle Info.
Not Supported Or Sto-red No Data.
Since DTCs Cleared
MIL Status ON
Misfire Monitor OK
Fuel System Mon OK
Comp. Component OK
Catalyst Mon INC
Htd Catalyst N/A
Evap System Mon INC
Sec Air System N/A
A/C Refrig Mon N/A
Oxygen Sens Mon OK
Oxygen Sens Htr OK
EGR System OK
Stored Codes
P0155 O2 Sensor Heater Circuit Bank 2 Sensor 1
P1131 Lack Of HO2S11 Switch - Sens Indicates Lean
Pending Codes
No pending codes are stored in the module!
View Freeze Frame
DTCFRZF P1131
FUELSYS1 CL_Fault
FUELSYS2 N/A
ETC(°C) 181
LONGFT1(%) 0.0
SHRTFT2(%) -6.3
LONGFT2(%) 0.0
RPM(/min) 1834
VSS(km/h) 17
O2 Monitor Test
O2 Bank1 Sensor1
Not Supported Or Sto-red No Data.
O2 Bank1 Sensor2
Not Supported Or Sto-red No Data.
O2 Bank2 Sensor1
Not Supported Or Sto-red No Data.
O2 Bank2 Sensor2
Not Supported Or Sto-red No Data.
On-Board Mon. Test
Not Supported Or Sto-red No Data.I'm going to search for a forum that will help me analyze the rest of the data... I think it's going above and beyond for here...

One test I have not yet done, using the scan tool, is a a component test that commands the vehicle's on-board computer to perform a leak test of the EVAP system. Which sounds great, but it warns that I need to first figure out how to stop the test once it has started... Strange... So I'm researching that now as well.

So when the code P1131 was set, you were going slow, the engine was pretty much at temp, but interestingly the long term fuel trims were at 0 (which is good, but somewhat unusual) yet the short term fuel trim was at -6.3%. That would indicate that the PCM was attempting to lean out the air/fuel ratio at the same time the bank 1, sensor 1 sensor was reporting a lean condition. Since the PCM was trying to send the mixture lean, that would seem to indicate that the problem may not be a vacuum leak.... I need to think about this one a bit.... I guess it's time to go wash the car.

-Rod

Thanks shorod, you're the best!

Keep in mind that the car runs really great, everything is tuned up, oiled up, and my MPG is relatively good.

If it helps, here is a link to a Word document that has the results of real-time data tests that the scanner performed. One test was done in town, and the other was done on the highway: http://rapidshare.com/files/134426113/2aug08_taurus_scanner.doc.html

I would use a wiring diagram and ohm the wires from the computer to the O2 sensors. I have had numerous wiring problems on Fords as I think you are getting to many codes.
Can you borrow a scope to look at how the plugs are firing. Every couple of months I used to get Saturns in the garage from a Parts store with a dozen codes and all it was was the harness Saturn used to fire the plugs.
Did you ever replace any wire to the sensors that was shielded and use normal wire this will really mess up a sensor.
Look at the ground strap for the computer and make sure the shielding ground wire is attached.
You can ohm all plug wires intermittant firing will set codes.
Cracks in the exhaust system will cause problems.
Make sure your timing is set correctly as this will cause numerous codes.
Normally replacing sensors with no change means you have other problems.

On your freeze frame data, it shows the ECT as being ETC(°C) 181 I am not real swift on the conversion, but isn't that rather high? 181 would be closer to normal for a farenheight reading. If so, that could be your problem. The ensuing codes could be a result of the PCM trying to correct for a faulty ECT.

On your freeze frame data, it shows the ECT as being ETC(°C) 181 I am not real swift on the conversion, but isn't that rather high? 181 would be closer to normal for a farenheight reading. If so, that could be your problem. The ensuing codes could be a result of the PCM trying to correct for a faulty ECT.

Good catch! Way to pay attention to details! I saw the 181 and filled in the units in my mind. That would equate to about 358 degrees F.

-Rod

Great going!

I'm learning about the ECT sensor now ( http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528003aabf ).

Seeing as this car has been to the mechanic several times in the past couple months, if the engine was REALLY running 357F (that isn't even possible... right?), then that would have caught... I would think.

So HOPEFULLY it is just a bad sensor.

It's strange, if you look at the live data that I linked to above, it shows the ECT readings steadily incrasing from 30 to 91oC (194oF)... Only in that once instance does it say 181oC...

Again, that may be your problem. It posted that temperature when the faults occured. That is the good thing about freeze frame data. It takes a snapshot a few seconds before and after the time the fault trips the trouble code. What happened when you erased the code and ran the vehiclew again? Sometime the PCM recieves a bad signal from somethimng and will trip the code. Let us know.

I am going to try clearing everything next. I TRIED to read the ohms, but I physically could not get the leads of my multimeter into the sensor on account of all sorts of things being in the way... It's buried... I did not see any corrosion on the sensors wiring at least.

I cleared everything and ran the scanner again while driving. The light came back on and the freeze frame showed the ECT at over 300F again...

So, after an hour of parking the car, while the engine was still hot, I set my multimeter to (auto) ohms and put the negative lead on the engine and the positive on the prong of the sensor (I have not taken off the sensor). It read... 10 mega-ohms... Obviously it should have read something in the kilo range, so what do you make of that? I tried it several times until I finally got into a (contorted) position where I could see the prong to put the positive lead on it. Does it sound like I'm doing something wrong?

http://fordfuelinjection.com/?p=28 This is a picture of an ECT sensor.
Are you on the correct wire?

If the sensor you're measuring only has one wire to it, you're on the wrong sensor. The Engine Coolant Temperature sensor should have two wires to it. The signal return is the gray/red wire and the sensor input wire is light green/red. You'll want to unplug the sensor and measure between the two leads on the sensor, not with respect to ground.

-Rod

Dittos on the ECT with two wires and the dash temp gauge with one wire. It needs to be measured with the connector off to test resistance with respect to temp. At 65 deg F expect 40,500 ohms. At normal operating temps of 180 to 220 deg F, expect 3800 to 1840 ohms. These things are cheap, so in doubt, replace it, but be sure to get a brass unit. One guy used three plastic ones in a year, what junk!?! If you aren't seeing these wild temperature spikes on the dash temp gauge, I'd suspect the ECT is bad, that and the out of range ohms you've measured.

When the car gets hot or after a hot drive with it off, does the radiator fan come on and off? The ECT is supposed to trigger the fans both when the engine is on and off.

Doh, I WAS testing the wrong sensor, the exact one you all think I was testing...

I will try again tonight!

And I will pay attention to the fan today too. It will be very hot today (it's parked in the sun), so after my 25 min drive home, I guess the fan should stay on after I turn the car off. I will take note.

OK, I found the correct sensor this time. It's very hard to get to, the metal pipe that it attaches to angles back towards the cars' cabin and I am not able to see the business end of it at all... However, I'm pretty sure I was able to get the leads in there and on the prongs correctly (I also noted that the cable connector did not have any corrosion in it). The meter read 3.82k ohms. Which may or may not be OK. I had just finished driving it about a half hour after it had sat in the sun in 95F weather all day. Tomorrow morning, before I drive it, I'll meter it again when I know what the temperature of everything is.

The link I put on a previous post gave ohm readings for various temperatures.
It also says to check the voltage. I would read it as it gives ideas and things to check. Check if your scanner will read the voltage for you as this gives you a much better idea what is going on and is more valuable. Its a lot easier also.
Temperature and ohms go together so you need engine temperature and ohms to compare to the chart.

Knowing the temperature this morning (75F), I checked the ohms on the ECT sensor again, it read 26.48kohms, which according to the chart here: http://www.autozone.com/az/cds/en_us/0900823d/80/1a/f7/5b/0900823d801af75b/repairInfoPages.htm is correct.

SIDE NOTE: My radiator fan is NOT staying on when the car is off after driving a half hour when the car has been in the sun in 95F weather all day. Is this a clue?

Base timing and wiring affect this censor. If it ohms correctly ohm wiring between sensor and computer. Check base timing as the radiator would be blowing a pressure cap at the temperature over 300 degrees F. Put ohm meter betweem the two connections to check if they are touching each other both ends unplugged. Also use a copper wire so the meter checks for resistance the length of the wire. If these tests are good buy a new sensor. I've found Fords are very sensative to base timing missing 10 degrees when changing a distributor will set off codes.

Rhandwor, I understand the part where I should check the entire length of the wiring for the sensor, I was going to pick up a back probe kit tonight to do just that. But I'm a little confused about what you are trying to say about a copper wire... And backtiming, I'm reading into that, I've never heard of it before.

The leads won't reach the whole length of the wire. So I use a copper wire so I can reach both ends of the wire.
The timing take a timing light and make your marks. Unplug the sprout and set base timing. You said you had a distributor.

Oh I see what you mean. I apparently do have a distributor, but I don't have a timing light so I'll save that test for later if I rule more things out.

I THINK I FIGURED IT ALL OUT

Very quickly as I do more research: My PCV valve is oily!!!!!!!! And there is a VERY good reason for it! If you read back to one of my first posts, a state inspection guy showed me a little section of vacuum hose that had completely collapsed. So I replaced it. Well, it turns out that that little section of hose connects DIRECTLY to my PCV valve, and I'm holding the valve right now, and it's VERY oily! Which, from what I've read, is exactly what you would expect if there is a hole in the hose, it will get clogged up.

Wouldn't that account for everything??

The PCV DOES rattle when I shake it, btw.

Clean it out with carb cleaner and put it back in or buy a new one. It indicates the engine is using oil and may have have internal problems.
You can always try it and clear codes but I think they will be back.

There is a brown, oily substance on the nipple of the fuel pressure regulator that I saw when I pulled off the vacuum tube (there was a little bit in the tube as well).

The brown stuff in the line is gas. So maybe the regulator has a hole in the diaphragm?

The engine just had a tune up about 2 months ago...

This is very possible this would cause other problems and soot up plugs.

Plugs, as in spark plugs?

I just had them replaced at the same time as the engine tune up, turns out they were the original plugs...

So, tomorrow morning I'm going to buy a new fuel pressure regulator and PCV valve. Then I'll clear the codes and see what happens.

A rich fuel mixture will soot up spark plugs. A trip on the expressway should clean them up if the engine is firing properly.

I changed out the PCV valve and fuel pressure regulator with new ones. I had to disconnect the battery so now the codes are cleared. I let the car run about 15 minutes while I did some other things and I kept the scanner attached to the car, but nothing popped up (of course, I didn't expect anything to). If the underlying problem with the codes has not been taken care of by these things, then I fully expect the engine light to turn on during my drive to or from work tomorrow. I will keep the scanner on and set to record when an error pops up. Since I've had this problem it has NEVER taken long for the engine light to come on once the codes are cleared.

And in regards to the spark plugs, I will be doing some 65mph driving tomorrow to work.

This should remove some codes but I'm not sure about all of them.

Me neither. If any codes come back on, I'm going to hit the library tomorrow to go to alldata.com and print out wiring diagrams so i can test some wires at the PCM.

OK, keep in mind that historically, it has taken about 20 miles for any codes to turn on after disconnecting the battery or clearing the codes with the scanner, and all codes have always come up at the same time. Yesterday the codes were cleared via the battery. This morning after less then a mile, the service engine soon light came on. The scanner was plugged in at the time and recorded live data then, and later when I was on the highway. Right now the scanner is reading 1 "stored code": P0155 ("O2 Sensor Heater Circuit Bank 2 Sensor 1") and 1 "Pending Code": P1131 ("Lack of HO2S11 Switch - Sens Indicates Lean"). I have never had a "pending code" before. THERE IS NO FREEZE FRAME DATA that my scanner recorded.

Remember, if it helps, I can always post the detailed data that the scanner records.

I would get some white out and mark your timing marks so you can easily see them. You can buy a light at Sears or ask some friends surely one of them has a light. If they will allow you to use it do it at their place. Make sure you have a wrench with you to loosen the distributor. I would drive for a day or so wipe the codes with your scanner as the computer has a learning process when the battery is disconnected. Then I would retest as some of your spark plugs probably were dirty.
You have made a lot of progress and I think you can make some more before doing pinpoint tests.

Hrmm, I might pick up one of these then, the price sure is right: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3343

I should point out though, that the initial ETC temp that the freeze frame reported on my scanner is probably incorrect in the units that it used to report the temp. In other words, I now believe that it was reporting the temp in F when it said it was reporting in C, which would mean that the ETC temp was just fine. I think this because if I look at the detailed data from when the scanner was recording data live, it reported everything in F and those temperatures were very reasonable. So I really don't think the coolant was any near 300F...

That test light should do the job if it is dim do it in the evening much easier to see if you don't have a garage. If the temperature was over 300 degrees F you would have been shut down. So I never believed the reading. Around 235 degrees the radiator cap would be blowing.

Let me explain a little more on the ECT. I am not saying the temperature of the engine is 181C. I am saying there was a problem that caused the PCM to read the temperature as 181C. If the PCM reads that, it will shut down a lot of the fuel, thereby giving a lean condition. There may be a chafed place in the wiring that id groundinf once in a while causing the code to trip. The speed is reading in Kmh so I feel the scan tool is reading all information in the same scale. Look for something that may be intermittent in nature. You may also have moved the wiring so it will cause the codes to return sooner.

I was planning on going to the library to hopefully access www.alldata.com (http://www.alldata.com) for free, but our libraries don't do that. From there I was going to print out the diagrams so I could test the wires connecting to the PCM. What they DO have is free access to an online version of Chilton's Repair Guide, that I can access from home. Though I haven't learned if that has the same diagrams in it or not.

And it turns out I do NOT have a distributor. I have a "distributorless ignition system", more specifically a " Electronic Ignition (EI– High Data Rate) Ignition System". So I'm researching what that is all about. Here is what Chilton says about it:

The Electronic Ignition (EI High Data Rate) system is used on the 3.0L DOHC engines. The system consists of the following components:

- Crankshaft Position (CKP) sensor
- Ignition coil
- Desired spark angle from the Powertrain Control Module (PCM)
- Related wiring

The Crankshaft Position (CKP) sensor is a variable reluctance sensor triggered by a 36 minus 1 tooth trigger wheel located inside the engine front cover. The sine wave signal generated from the CKP sensor is known as the CKP sensor signal. This signal provides two types of information to the Powertrain Control Module (PCM): the position of the crankshaft in 10 degree increments and crankshaft speed (rpm). The PCM will use this information along with the spark advance information to determine when to turn the ignition coil on or off.

The ignition coil contains separate coils. Each coil is controlled by the PCM through two coil leads. Each coil activates two spark plugs simultaneously.

One spark plug is activated on the compression stroke. This spark plug uses the majority of the ignition coil's stored energy. The other plug is activated simultaneously on the exhaust stroke. This plug will use very little of the coil's stored energy. These two spark plugs are connected in series so that the firing voltage of one spark plug will be negative with respect to ground and the other spark plug will be positive with respect to ground.

For what it's worth, here is what Chilton says about P0155:

Trouble Code: P0155 (3.0L V6 VIN S Auto)
HO2S-21 (Bank 2 Sensor 1) Heater Circuit Malfunction

Number of Trips to Set Code: 2

OBD II Monitor Type: CCM Details
Indicators: MIL Details

Trouble Code Conditions:
Engine running for 5 minutes, and the PCM detected an open or shorted condition, or excessive current draw in the heater circuit.

Possible Causes:

* HO2S heater power circuit is open
* HO2S heater ground circuit is open
* HO2S signal tracking (due to oil or moisture in the connector)
* HO2S is damaged or has failed
* PCM has failed

So, using the online version of Chilton's wiring diagrams for the PCM, I'm going to test the wires going into the PCM to see if one of them is damaged... after work today.

You have strange problems and have installed 1 or 2 sensors for each problem. Also I asked and you said you had a distributor.
Is this a very high mileage car? Do your wires look like the insulation is cracking from sitting outside in the heat. I'm surprised your mechanic didn't check fuel pressure which would have led him to the bad pressure regulator.
Did this start on one day or been going on and gradually gotten worse?
If high mileage has the timing chain been replaced?
As way2old stated I've had wires wear and touch the copper wire together.
This is a likely problem and I would check before buying a new computer.

I thought I read that I had a distributor. But physically not finding one, I checked Chilton's and learned that I didn't...

The car has 120k miles on it. When the mechanic found the initial codes, all he did was change out the O2 sensors... twice... and used his scan tool/computer to run tests. I won't be using him again. I didn't know any better then, now I do. Basically I've never had a good experience with any mechanic, that is why I'm going to try to fix things on my own from now on (with exceptions, of course).

I'm pretty sure that the timing chain has never been replaced, I only recently learned that it existed, and I think I would remember if it was brought up before as a problem.

I used my multimeter to test the ECT sensor, with the wires pulled, it read 12kohms (car has been parked for a couple hours). I then pulled the bundle of wires connected to the PCM and test wire's 38 (ECT sensor) and 91 (signal return), that test came back as 12kohms as well.

So, I guess that means ECT wiring is fine at least. Tomorrow I will put the car up on ramps and follow the wires for the faulty O2 sensor. Since this sensor (

See my post #7 for temperature and ohms ranges you should measure at the ECT and go from there.

Basically I've never had a good experience with any mechanic, that is why I'm going to try to fix things on my own from now on (with exceptions, of course).

OUCH. That hurts. I have been a mechanic/technician since 1965

Yeah, I should have followed that sentence up with "... no disrespect." Just venting, pay no mind too the frustrated noob.

Gah, it looks like a good chunk of my last was cut off... Now I don't remember what I wrote.

So, I discovered that I still had the original B2S1 sensor in the car, and it looked really rough. So I replaced it and cleared the codes.

Now I get this after driving a bit of city/highway today:

- The Check Engine Light did NOT come on.
- No STORED Codes.
- 2 PENDING Codes: P0135 & P0155

FREEZE FRAME:
DTCFRZF P0155 <-- NOTE: I have not had this code in the Freeze Frame before...
FUELSYS1 CL <-- NOTE: In all the other Freeze Frames, this has been "CL_FAULT"
FUELSYS2 N/A
LOAD_PCT(%) 52.2
ETC(C) 181
SHRTFT1 -6.3
LONGFT1(%) -1.6
SHRTFT2(%) -1.6
LONGFT2(%) -3.1
RPM(/MIN) 2112
VSS(KM/H) 45

I/M READYNESS TEST:
Oxygen Sensors Monitor: INCONCLUSIVE
Oxygen Sensor Heater Monitor: INCONCLUSIVE
Evaporative System Monitor: OK <-- NOTE: Yesterday this was "INCONCLUSIVE"

So, I discovered that I still had the original B2S1 sensor in the car, and it looked really rough. So I replaced it and cleared the codes.

Now I get this after driving a bit of city/highway today:

- The Check Engine Light did NOT come on.
- No STORED Codes.
- 2 PENDING Codes: P0135 & P0155

FREEZE FRAME:
DTCFRZF P0155 <-- NOTE: I have not had this code in the Freeze Frame before...
FUELSYS1 CL <-- NOTE: In all the other Freeze Frames, this has been "CL_FAULT"
FUELSYS2 N/A
LOAD_PCT(%) 52.2
ETC(C) 181
SHRTFT1 -6.3
LONGFT1(%) -1.6
SHRTFT2(%) -1.6
LONGFT2(%) -3.1
RPM(/MIN) 2112
VSS(KM/H) 45

I/M READYNESS TEST:
Oxygen Sensors Monitor: INCONCLUSIVE
Oxygen Sensor Heater Monitor: INCONCLUSIVE
Evaporative System Monitor: OK <-- NOTE: Yesterday this was "INCONCLUSIVE"

Look at the red readings again. They both are reading on the metric scale. The 181 C reading is bogus and more than likely causing the problem. You need to find out if it is the sensor that is bad, the wiring that is bad, or the PCM that is causing the problem. The 135 and 155 are for both front O2 sensors. 135 is bank 1 upstream heater circuit. 155 is bank 2 upstream circuit failure (short versions of codes).