P1131, P0171, P1151

[jca1980]

I'm the first to admit it. I have been a negligent owner.

Do to a lack of spare time I have been driving around (while not much I ride my bike to work) all summer with the glare of the CEL in my eyes. During this time I have checked and cleared the codes (currently P1131, P1151 & P0171 pending) numerous times. Ignorance is bliss.

A few weeks ago the car started to stall occasionally at idle, but more common was just a quick drop in rpm at idle followed by a spike and then normal idle. Otherwise the car has been idling slightly rough.

In the past few days the CEL cleared its self and I have noticed a HUGE return in performance.

In any event, I finally have some time to deal with this so my first plan of attack is to replace the two upstream O2 sensors. My question is, since my car has been running *rich for so long should I be concerned with the plugs or anything else as well?

My gas millage has be horrible, my last tank took me just beyond 300kms. I'm considering replacing the fuel filter as well.

Comments, suggestions, adivce, and scolding, all welcome,

Thanks,
jc

[projectSHO89]

If anything, I'd be concerned about:

1) That pesky vacuum leak

2) What all that unburned fuel has done to your cats and am wondering how long before the P0420/P0430 sho up.

You car has actually been running rich, not lean.

Steve

[jca1980]

If anything, I'd be concerned about:
...
1) That pesky vacuum leak
...
Steve

I did a vacuum test on the EGR valve.. and it was ok. Is that what you are refering to?

[Tony2005]

Check for a broken vacuum hose, loose clamps at air intake duct (accordian tube), air filter housing, etc. Spray with carb cleaner or propane. When the idle changes, you found the leak.

http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm