'02 Rodeo Headache

[BUCHO_LE1]

I can't seem to fix this problem with my '02 Rodeo. I have replaced the EGR valve, all four O2 sensors, fuel filter, and the MAF sensor but I still get a CEL light that illuminates and occasionally blinks. I also continuously get several codes every time I stop into Auto Zone. The codes are P0101 MAF sensor performance, P0401 EGR system fault, P0161 O2 Bank 2 heater condition, P0172 Air/Fuel ratio in only one bank, P0175 Rich/Lean condition Bank 2.

Please help!!!! I hate that my Rodeo is sick and I can't fix it!!!!!

[XR400R]

How does it run?

Does it surge at all; is the idle steady?

Has the intake manifold gasket been replaced ever/recently?

[BUCHO_LE1]

The idle is weird. It only idles funny when in park or neutral and that is not always happening. When I shift into drive or reverse it runs fine. Sometimes it runs perfectly fine and then other times it stalls completely when I shift it.

The intake manifold gasket has not been replaced yet. I am thinking that is what I am going to attempt next. Is there a place to find step by step instructions. I am a helicopter mechanic so the only engine I have worked on in depth is turbine engines.

[XR400R]

I would agree with you, IMG replacement is the next step here.

There is some info out there (not a lot). Also, you need a service manual if you don't already have one. If you don't, let me know & I'll be glad to PM you with a link to a file sharing site where I put a manual for downloading at someone else's request.

As an aircraft mechanic, replacement of the IMG should be a relatively simple task. While you're in there, I would recommend you replace the thermostat if it has not been done. It is buried beneath the manifold & you basically waste the manifold gasket when you try to get to it. Now's a good time to do that. I recommend using only Isuzu-OEM thermostat. They seem to last a really long time (I replaced mine at 100K miles without failure).

[amigo-2k]

2x... I've had my IMG replaced 2x with the same issues you have.

[BUCHO_LE1]

Thanks. I do not have a repair manual so that would be great if you could send me any information on the replacement of the Intake manifold gasket or anything else for repairing my Rodeo.

I will replace the gasket tonight if I can figure it out and fill you in on the repair.

Thanks a lot!!!! I hope this works!

[XR400R]

PM with link(s) sent.

Also, I have a short .pdf file that describes the process on a 2nd Rodeo (with pics) that may be of help. If you will PM me with an e-mail address, I will send it along.

Just a couple of tips from my experience:

Careful removing the fuel rail/injectors. They pull straight out (after removing the harness) but be ginger about it. It's easy to screw up the two O-rings on each injector. Best to replace them if you can, & put a bit of motor oil on them at reinstall to keep from damaging them on reinstall.

Also, have 4-5 cans of brake cleaner ready to clean inside of both halves of the IM. It will be totally black & brake cleaner does a better/quicker job than any thing else I've found.

One last tip, BE SURE & clean out that long, EGR transfer pipe running the length of the lower manifold section. It tends to get gummed/carboned up real quickly resulting in poor/no functioning of the EGR valve, resulting in bad knocking on reglar gas.

Best O luck.