SpaceRockr

I was driving home from work yesterday, and I was coasting down a road at 45, as I stepped on the gas the car, started running very rough, like I lost a cylinder. I restarted at the next light, issue still there. I was able limp the car home, another 10 miles with no warning lights etc. Once I got home I restarted the car, same issue, warning light on.

I read edu code, its a 25. I rest the ecu overnight and let the car cool, started the car cold this morning same issue. Does anyone know what should be replacing with a code 25 / running lean? Would an O2 Sensor cause this? I thought it needed to heat to work?

Thanks in advance

scblackout

iTrader: (2)

Sounds very similar to what I have been fighting for months now. Best way to describe my problem is it feels like 1-2 cyl drop, runs very rough, hardly any power like 10%. Problem comes and goes. I would get rotating codes from o2 sensors, crankshaft sensor sometimes, lean bank 1, you name it. It was always different.

We don't have limp mode in our model years as we are not fly by wire throttle, so that is not the issue. I think limp mode was introduced in 97 with fly by wire.

I believe I may have finally solved the problem and here are all the steps I took. You may or may not need to do any or all of these steps.

Replaced these items:
spark plugs, wires, cap, rotor, new distributor o-ring, o2 sensors, all vacuum hoses, pcv valve and grommet, fuel filter, fuel lines (lube shop twisted my fuel line at filter without bothering to tell me), fuel pump, battery, sent ecu to tanin, checked every single engine harness connection, remove, clean, replace.

In the end I believe it turned out to be a poorly manufactured pcv grommet. One side of the grommet was totally flat so it would not seat into the valve cover. This was causing a small amt of oil to leak out into the spark plug channel which corrupted the electrical signal. Once we cleaned this all out and replaced the plugs and grommet the car seems to run properly. At least for a few days now. Of course we did a full compression and leakdown test as well as a tuneup to 10 degrees (my best guess in reading around)

Lesson learned was that it could be the smallest simple fix yet very hard to troubleshoot. I would start by doing all maintenance items I listed above as if you haven't recently it is a good time anyhow. After that it is a matter of chasing hidden gremlins which really sucks if needed. Good luck.

SpaceRockr

Thanks for your reply. It ended up to be a bad spark plug on cylinder 5.