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Egr ...........check Engine Light?????


booner
01-03-2004, 01:22 AM
Hey ........first of all great site .........thanks . Second ..... the check engine light has appeard on my dash . The wife is afaid to drive the car , do this pose any seriouse trouble if we keep driviving it . The car has only 48k miles it's 5 years old and has been babed.I have read the it could be some thing like a plugged sesour line that just needs to be blown out . The really funny thing is about 1 year ago this happenend after a simple oil change at the dealer,they had the car for 4 days and "They coulnd'nt find any thing wrong" the dealer told me this. So needless to say I wont take my care back there . Any one please if you could take a minute and reply to this site or to me at mattdeg65@comcast.net thanks again god bless happy new year

beyondloadedSE
01-10-2004, 12:23 AM
Chances are its a bad 02 sensor. Mine check engine light will come on sometimes and go off the next day. It always comes on during city driving and goes off after highway driving. Take it to Autozone and theyll pull the code for free and tell you what it is.

clydes270
01-21-2004, 07:18 PM
If they read the codes and there are multiples, suspect that the EGR has clogged the throttle body.

I just serviced a 1997 Mystique 2.5L w/ 55,000 miles. Codes were for the EGR, PFE, O2, and Canister Purge solenoid. Carbon from EGR had plugged the ports behind the throttle body. I removed the intake to get a good overall cleaning.

All this resulted from not driving the engine hard, after warm. Should rev the engine above 5000 rpm, once or twice a month to kick the carbon out. An entrance ramp on the highway is a good place to run the car.

FYI, there are four O2 sensors on the 1997. Two fore and two aft. Cost is around $60 to $120 each (depends where you buy) to experiment.

Mango113
06-01-2004, 09:03 PM
OK, I have a 98 with V6 and 5 spd. Check engine light has been on for 6 months. Dealer says catalytic converter for $1000+. I'll try Autozone, but does the V6 and 5 spd have any history with check engine light issues?

beyondloadedSE
06-01-2004, 10:14 PM
OK, I have a 98 with V6 and 5 spd. Check engine light has been on for 6 months. Dealer says catalytic converter for $1000+. I'll try Autozone, but does the V6 and 5 spd have any history with check engine light issues?

$1000!!!! :screwy: Are they out of their minds?! :banghead: First of all, all ford cats have an 8 year/80,000 mile warranty, so if it needs to be replaced, theyll do it for free as long as your still within that warranty. If you are out of warranty, you could buy a high flow cat for like $150 and have a muffler place weld it for you for another $100. I swear...they should just call them stealerships instead of dealerships. Try autozone first and get the codes pulled. If they dont have an OBD-II manual on hand after they pull the codes, ill be more than happy to tell you what they pertain to.

Mango113
06-03-2004, 09:00 PM
Haven't made it to Autozone yet, but thanks for the advice! I read on contour.org that this car has 4 O2 sensors and that they wear out. Is that more likely than a dead cat? (car has 93,000 mi). Are they a DIY replacement?

beyondloadedSE
06-03-2004, 09:19 PM
Haven't made it to Autozone yet, but thanks for the advice! I read on contour.org that this car has 4 O2 sensors and that they wear out. Is that more likely than a dead cat? (car has 93,000 mi). Are they a DIY replacement?


Its really hard to say without given any codes. Youll be able to really tell if you have clogged cat. Intake will be louder, loss of backpressure, and extreme loss of performance. I know when mine was clogged, it would take me 16 seconds at wide open throttle just to get from 0-60. I know on the 95-97 models there was a catalytic convertor recall because the main cat was clogging. I cant remember if this was an issue on the post 98s. Go to autozone and we'll go from there.

Mango113
06-05-2004, 11:33 AM
Just came from Autozone (what a great deal - the manager came out and pulled the codes, made some recommendations - no pressure to buy anything!)

Two codes come up 420 and 1131

Think it's worth replacing the upstream O2 sensors?

beyondloadedSE
06-10-2004, 12:43 AM
Two codes come up 420 and 1131

Think it's worth replacing the upstream O2 sensors?

If the O2 sensors have never been replaced, id upgrade to some Bosch O2 sensors.

wlovett
10-11-2004, 09:15 PM
I have a 1996 Mercury Mystique LS 2.5L V6. Check engine light is on. I went to AutoZone and got the following codes. I assume that I should replace the EGR valve, I would just like someone elses opinion. The codes are below and any feedback is greatly appreciated. Thanks

DTC P0401
EGR Flow
Insufficient

DTC P0430
Catalyst Efficiency
Below Threshold
(Bank 2)

DTC P0171
System Too Lean
(Bank 1)

DTC P0174
System Too Lean
(Bank 2)

beyondloadedSE
10-11-2004, 10:32 PM
sounds like the culprit to me.

wlovett
10-12-2004, 09:08 PM
BeyondloadedSE,

Thanks for the quick reply. Do you know where the ERG valve is located? Is this something I can replace easily myself? Thanks again....

Mango113
10-16-2004, 04:16 PM
If the O2 sensors have never been replaced, id upgrade to some Bosch O2 sensors.

Thought I'd give an update.
Replaced the O2 sensor (Bosch) by the firewall. The check engine light went off, but came back on a few days later. Then, after about a week, it went off and has been off ever since (knock on wood). My mechanic says it's because the system needed to go thru 3 complete engine cycles without an error. (He didn't pull the fuses mentioned elsewhere in this forum to reset the computer).

So, the Ford place tried to convince me to replace the cats. I replaced one O2 sensor instead and the problem is solved.
Thanks to this forum for saving me money!

By the way, they say that you won't be able to pass the annual NY state inspection in 2005 with a check engine light on anymore. My mechanic says they have to send the computer codes to the state so you can't just turn off the light either. Could get interesting.

drmattdogg
10-20-2004, 05:09 PM
interesting. i just recently had my light on and it came back as an inefficient catalytic converter also. they assured me at the shop that i could drive with the light on and it wouldnt create any problems if it happend to come back on. maybe ill check into this O2 sensor if it comes back on. and i havnt really noticed any preformance drops either. i guess that is a good sign.

clydes270
11-24-2004, 02:17 PM
All those codes sounds like what I just went through. I replaced no parts. Just removed the Intank Manifold and soaked it in cleaner for 2 days. It was really clogged. Then, I washed it out with a hose, dried it for a few hours in the sun. Now, no codes. Now, I make sure that I hit the redline once in a while each month.

taximan
01-02-2005, 06:06 PM
All those codes sounds like what I just went through. I replaced no parts. Just removed the Intank Manifold and soaked it in cleaner for 2 days. It was really clogged. Then, I washed it out with a hose, dried it for a few hours in the sun. Now, no codes. Now, I make sure that I hit the redline once in a while each month.


ok, this cat below threshold thing is very common. We run a fleet of crown vic's and we have at least 3 cars with a engine light because of that. that is why i joined this forum.

there is a problem with the ford computers. i think this was even acknowledged by ford now. the computer just doesnt handle the O2 sensor info right when they have been on the car for a while. And no they aren't just bad O2s. Also if you replace one sensor you will get this code sometimes because the banks wont be even enough or something like that.

either way i know there is a fix for this problem. you can get the comp reflashed to accept a wider range. I dont know where to get it but i know its out there. and given how much these parts cost im sure it will save me cash to find it.

help?

galaxygrl2005
01-08-2005, 08:07 PM
I have a 95 mercury mystique and the check engine light has been intermittenly going on and off. Employees from both Autozone and Jiffy Lube were unable to find a place to plug in an OBD-II reader to diagnose the problem. I'm pretty sure it is not in the same place as the 96-2000 models. Does anyone know if 95 mercury mystiques have a place to plug in an OBD-II reader? If not, what is the best way to diagnose the issue? Thanks!

Marathonman
01-08-2005, 08:25 PM
ok, this cat below threshold thing is very common. We run a fleet of crown vic's and we have at least 3 cars with a engine light because of that. that is why i joined this forum.

there is a problem with the ford computers. i think this was even acknowledged by ford now. the computer just doesnt handle the O2 sensor info right when they have been on the car for a while. And no they aren't just bad O2s. Also if you replace one sensor you will get this code sometimes because the banks wont be even enough or something like that.

either way i know there is a fix for this problem. you can get the comp reflashed to accept a wider range. I dont know where to get it but i know its out there. and given how much these parts cost im sure it will save me cash to find it.

help?Do you have anymore information on this Problem or know where I can find more? I think I'm haveing this problem with my Sable.

whirly1996
01-21-2005, 12:03 PM
I own a 2000 mystique just came back from a trip to Minnesota on the way home check engine light came on I figured no big deal this has happened to me before due to the gas cap not being put back on right. about 900 miles into my trip the car starts chugging on any incline i.e on ramps ect. got home by the grace of Luck had a mechanic look at it and he said I need a new catyalitic converter he checked into prices and said this would run me almost 1,000 bucks. called Mercury to see what they would charge for a new converter and I almost fell over they quoted me $1,800.. well in the mean time my timing belt now went out cost me $350 bucks to get that replaced. needed the car to get to work so we just took off the converter till I can get the cash to replace it. and low and behold the check engine light is still on darn pesky thing lol

Fgreco
03-23-2005, 07:08 PM
I have the same problem with the check engine light. Ive been to two guys the first gave me codes and said it was thousands of dollars. I didnt beleave them and whent back to my trusty mechanic and he pulled up only one code that said it was the catylitic converter. They reset the light it took about a month and it came on agian Iam going tomarrow to see what it is.

quilcene
06-21-2005, 06:24 PM
AuroZOne Told me the O2 sensor was bad/ How do I find those under the hood specifically please.??
I kinda know what it looks like but there are a few things under there appearing to to be the O2 Sensor.
Gratias--

beyondloadedSE
06-22-2005, 12:25 AM
AuroZOne Told me the O2 sensor was bad/ How do I find those under the hood specifically please.??
I kinda know what it looks like but there are a few things under there appearing to to be the O2 Sensor.
Gratias--

If it screws into the exhaust manifold, its an 02 sensor.

quilcene
06-22-2005, 06:31 PM
All those codes sounds like what I just went through. I replaced no parts. Just removed the Intank Manifold and soaked it in cleaner for 2 days. It was really clogged. Then, I washed it out with a hose, dried it for a few hours in the sun. Now, no codes. Now, I make sure that I hit the redline once in a while each month.


Where is the O2 Sensor precisely--???

beyondloadedSE
06-22-2005, 11:37 PM
Where is the O2 Sensor precisely--???

depends...what year and engine type?

quilcene
06-23-2005, 12:52 AM
depends...what year and engine type?


2.5 L V6
98 Mystique

I sure could use a diagram to find it-
its nigh impossible to get out of the 1989 Ranger 4 cyl I have

But it looks like it may be on top in the Mystique
so one can get to it with a wrench easily.hopefully...

Thanks''

quilcene
06-23-2005, 12:53 AM
Oh Bye the way''
are there two that need to be removed or will one do. The sensor said something about Bank one and Bank two ___

beyondloadedSE
06-23-2005, 02:53 PM
Oh Bye the way''
are there two that need to be removed or will one do. The sensor said something about Bank one and Bank two ___

bank 1 and bank 2 refer to both sides of the engine. bank 1 being the rear of the engine and bank 2 being the front. It should have said upstream or downstream to refer to the 02 sensor and where its located on the manifold.

unclereggie
04-18-2007, 04:37 PM
My daughter and her husband recently purchased a new car and gave me their 1998 Mercury Mystique LS Sport 2.5L V6.

When I attempted to inspect it in NYS, I was told that it would not pass inspection because the Check Engine light was on. I was further told that there was such a laundry list of possible causes to invesitigate that "it might not be worth it to me to proceed."

Say what? I should just junk the car because of a "Check Engine" light? No freaking way! Needless to say, I took the car home.

The inspection report stated that OBDII diagnostic codes P0171 and P0174 were present. I began to investigate these codes via the web and found several resources of valuable information, especially including this forum. Following a bit of sage advice I encountered here - try the simple first - here is what I did:

Incidentally, I am a total novice so bear with me...

I first located the Mass Air Flow (MAF) sensor between the air filter compartment and the ??intake manifold?? I discovered that I would need tamper proof star bits to remove the MAF. Off I went to the Advance Auto Parts store. For $22 I purchased the start bits, electrical contact point cleaning spray and a new air filter.

Opening the air filter compartment, I discovered what must have been the original 1998 air filter. It was so dirty that no air could possibly flow through it. Dirt literally fell off it in clumps and the compartment was full of sand and pine needles. I cleaned everything up and installed the new air filter.

Next I removed the MAF sensor. It did not look particularily dirty but one of the tiny wire coils did look a bit discolored. I thoroughly spray-cleaned the two wire coils using the contact point spay cleaner employing the furnished straw to direct and concentrate the spray on the wire coils. I then replaced the MAF sensor.

I do not own a diagnostic unit, so to erase the stored OBDII codes I disconnected the battery cable and went for lunch. After lunch, I reconnected the battery cable and started the car - no "Check Engine" light of course. I took the car out and up the highway for a 20-mile round trip and shut it off. I restarted it - no "Check Engine" light. Twenty minutes later I repeated the same trip, shut the car off and restarted it - no "Check Engine" light.

I drove the car again later today and still no "Check Engine" light. Tomorrow I will take the car to have the inspection completed at no further cost than the NYS fee. Had I owned the proper bits and the spray, my only added expense would have been the $7 air filter.

Needless to say, I will not visit the same inspection station again.

dave46052
08-30-2014, 07:55 AM
2000 Merc Mystique with the 2.5 V6. Check engine light has been on a long while. Had the EGR valve replaced recently, didn't help much. The engine surges at highway speeds, 60-70 mph. Around town it runs fine. If the carbon needs cleaned from the manifold, how much can I expect to pay? I've but hundreds of $$$ in this car and my patience is wearing thin. Thanks. (I know the cat converters are also throwing codes.)

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