I have several codes showing for our V6. P0171, P0174, P0155 and P0300.
The guy at Advance Auto Parts says that two of the O2 sensors and the spark plugs need to be replaced. The plugs were installed during the 100K service by the dealer and the truck has been driven 32K since then. I am wondering if they have become fouled by the failed O2 sensors. It appears that the CEL codes are generic and not specific to Isuzu. Can they be interpreted further? Cna one tell from the codes which sensors have actually failed?

P0171 = system too lean bank 1
P0174 = system too lean bank 2
P0155 = O2 sensor 1 bank 2 heater circuit malfunction
P0300 = random/multiple misfires

A WHOLE bunch of stuff going on here. The 171, 174 and 300 codes could be a bad intake manifold gasket or a pc of dirt stuck on the MAF sensor. Nothing you can do for the P0155 aside from changeout the drivers side upstream O2 sensor (DO NOT replace any other O2 sensor than that!). The heater blew out on that same exact sensor on my 2002 at around 20-30Kmi IIRC. Keep in mind the 2002 rodeo 3.2L uses 'unique' O2 sensors. Multiple trips to parts stores and even mail order got me the wrong sensor every time. I finally got the correct O2 sensor from stcharlesauto for ~$120:crying: .

Joel

Joel,

I am dealing with some of the same CEL stuff... I have the Iridium plugs installed now which are being replaced today once the stock "Ion Sensing" Densos show up.

I was thinking about going ahead with the o2 sensor replacement (all 4) but when searching the online part stores I see that some show that all 4 sensors are the same and that some show 2 sensors are one part number and the other 2 are a different part number. I found the 02 sensors for $49 -$59 which I like price wise... so what you are saying is that ordering from St Charles Isuzu is the only way to go? What about the part numbers... All the same or is there a difference?

Also, cleaning the MAF... best method? What to use? Cotton swabs, etc.

Thanks for any info to us newbs!

Have fun!

John - 2001 Rodeo Sport v6, 4x4, Auto Trans.

John, on an OBDII compliant vehicle (1996+) I personally would never touch an O2 sensor unless you are getting a P0130 through P0167 code(s). http://www.troublecodes.net/OBD2/Pcodes.shtml Those are the only codes that mean an O2 sensor is not doing it's job. The 2 O2 sensors downstream of the catalytic converters do nothing more than monitor catalytic converter function. They are nothing but a go/no-go gauge. For a MAF cleaning, just blast the sensor clean with a spray can of electronics / electrical parts cleaner. I've used a swab to remove debris, but it's risky. Denso spark plugs are your best bet.

Joel

As it turns out a part of my problem was the MAF. We used a CRC product made specifically for cleaning the MAF sensor. You can get it online at Midway or your local Autozone.

http://www.crcindustries.com/files/MAF%20Sell%20Sheet%20Web.pdf


Joel,

I am dealing with some of the same CEL stuff... I have the Iridium plugs installed now which are being replaced today once the stock "Ion Sensing" Densos show up.

I was thinking about going ahead with the o2 sensor replacement (all 4) but when searching the online part stores I see that some show that all 4 sensors are the same and that some show 2 sensors are one part number and the other 2 are a different part number. I found the 02 sensors for $49 -$59 which I like price wise... so what you are saying is that ordering from St Charles Isuzu is the only way to go? What about the part numbers... All the same or is there a difference?

Also, cleaning the MAF... best method? What to use? Cotton swabs, etc.

Thanks for any info to us newbs!

Have fun!

John - 2001 Rodeo Sport v6, 4x4, Auto Trans.

Thanks. We installed a Bosch 13193 O2 sensor and it seems to be working OK. The code is gone for now at least.
The MAF was also a part of the problem as you suggested, it was cruddy, and we used a cleaner specifically for that from CRC. The improvement in engine idle was noticeable.
Haven't dealt with the plugs but the dealer installed NGK's at 100K miles.
We live in a rural area and 99% of my driving is on highways and interstates. No local traffic lights to slow you down so I don't really notice low end performance that much.


P0171 = system too lean bank 1
P0174 = system too lean bank 2
P0155 = O2 sensor 1 bank 2 heater circuit malfunction
P0300 = random/multiple misfires

A WHOLE bunch of stuff going on here. The 171, 174 and 300 codes could be a bad intake manifold gasket or a pc of dirt stuck on the MAF sensor. Nothing you can do for the P0155 aside from changeout the drivers side upstream O2 sensor (DO NOT replace any other O2 sensor than that!). The heater blew out on that same exact sensor on my 2002 at around 20-30Kmi IIRC. Keep in mind the 2002 rodeo 3.2L uses 'unique' O2 sensors. Multiple trips to parts stores and even mail order got me the wrong sensor every time. I finally got the correct O2 sensor from stcharlesauto for ~$120:crying: .

Joel

Update;

I changed the plugs to the Denso Double Platinum (stock). CEL was still there after the swap. (Yes, I did remove the battery cable during the swap) Rolled over to Oreilly Auto Parts for the CRC MAF sensor cleaner... sprayed the MAF... CEL is gone. BUT the car ran funny at first... kind of like I lost some power. So I will see what tomorrow brings. Freeway driving will tell me a lot. I am hoping that the CEL is gone for good... it has been coming and going so i am not convinced that i am in the promise land just yet! If I get it again I will see what the EGR cleaning process will do. Just updating my progress as I see others are going through the same general stuff as I am.

johngyver

Ours ran "funny" too as I drove it back from the shop, about 5 miles and the idle was a little lumpy. It sat overnight and I drove it to the office, about 40 miles and it ran much better. Idle was smooth no hesitation, etc.

Update;

I changed the plugs to the Denso Double Platinum (stock). CEL was still there after the swap. (Yes, I did remove the battery cable during the swap) Rolled over to Oreilly Auto Parts for the CRC MAF sensor cleaner... sprayed the MAF... CEL is gone. BUT the car ran funny at first... kind of like I lost some power. So I will see what tomorrow brings. Freeway driving will tell me a lot. I am hoping that the CEL is gone for good... it has been coming and going so i am not convinced that i am in the promise land just yet! If I get it again I will see what the EGR cleaning process will do. Just updating my progress as I see others are going through the same general stuff as I am.

johngyver

Ours ran "funny" too as I drove it back from the shop, about 5 miles and the idle was a little lumpy. It sat overnight and I drove it to the office, about 40 miles and it ran much better. Idle was smooth no hesitation, etc.

I went to the gym early this morning... about a mile drive. No CEL and it ran a lot better than it did last night. I am on my way to the office which is all freeway. I am an aggressive driver so I will work the system pretty good. I hope to see the CEL still gone and a much improved response. Thanks for your feedback... it made me feel easier knowing that you felt the same thing after the MAF cleaning. Will post back with more info.

Have fun!

johngyver

I am going to make the MAF cleaning a regular service as CRC recommends, probably tie it to air filter replacement. I am really impressed with the job the cleaner does. Sort of melted whatever was on the elements which were pretty gnarly.


I went to the gym early this morning... about a mile drive. No CEL and it ran a lot better than it did last night. I am on my way to the office which is all freeway. I am an aggressive driver so I will work the system pretty good. I hope to see the CEL still gone and a much improved response. Thanks for your feedback... it made me feel easier knowing that you felt the same thing after the MAF cleaning. Will post back with more info.

Have fun!

johngyver