It ran fine to work and then when I went to start it to come home it started but was really lumpy and once warmed up it won't hold idle. The odd thing is the exhaust smells rich?

I'm kinda stumped.

Would an exhaust leak ahead of the o2 sensor or the sensor itself cause this? I can smell exhaust inside when driving and it kinda sounds like there is a leak but when I get out to check it dies.

It could, if the leak lets in fresh air, that would bump up the sensor's O2 reading, telling the ECU the engine is running lean and it would compensate by increasing the fuel.

Hmm yea but what about the really lumpy idle?

It may not me that it is rich so much as just not burning the fuel. The idle is really lumpy and doesn't completely smooth out till around 2k.

Hmm I'm getting code 25 which could mean:

AIR/FUEL RATIO LEAN INDICATOR--LEAN SIGNAL SENT TO ECU FROM O2 SENSOR
--INJECTOR FAULT(S)

--FUEL PRESSURE

--OXYGEN SENSOR

--AIRFLOW METER OR MAP SENSOR

--IGNITION


What is the best way to procede in narrowing it down?
--ECU

Pull the plugs, see what they tell you.

Can't pull the plug till the weekend but I did fix a small hole in the intake tube that only made it run a little better but problem still remains. Intake tube looks like there aren't any leaks.

It is deffinately running rich as there was fuel in the intake tube. If the o2 sensor is toast will it cause this problem.

Sounds like an intake tube to me now. If you already found a hole there is probably more there than meets the eye. Mine cracked on the bottom side and caused havoc until I figured it out. Have you lost any power or just poor idle? It caused me to lose alot of power though, that's why I'm curious if overall performance is being effected.

Check your O2 sensor w/ an ohmmeter, otherwise I have an extra intake tube lying around that I can get rid of if needed.

My list of trouble shooting would go like this, intake tube, vaccuumm lines, vsv's, egr, O2 sensor, tps, mas, then I would look at the fuel system, pressure regulator, overall pressure, return, etc. I would think that the problem lies somewhere in there but if not, the ecu, or maybe even the intake and plenum gaskets sprung a leak, who knows?

Is the overall performance effected or just idle?

Performance above 2k RPM is fine its just from about 1500 RPM and lower that the things get lumpy and idle is horrible almost like a diesel that is cold.

Well I installed an o2 sensor that has been waiting to go in for a couple months with no effect. Then I tried running it with the VAFM unplugged and it is miles better then plugging the VAFM back in and it dies. So it looks like the VAFM is shot. Is there a good online retailer for these new?