2002 Chevy Camaro rough idle with O2 sensor error code

CHUCK NOLAN

MEMBER
2002 CHEVROLET CAMARO
V8
2WD
AUTOMATIC
83,000 MILES

The z28 LS1 idles rough with rpms at about 500. The engine has plenty of power and runs well. Along with the rough idle there is a O2 sensor error code that comes and goes. It seems that when the idle smooths out then O2 sensor error code clears.

Saturday, January 16th, 2010 AT 8:49 PM

1 Reply

ERNEST CLARK

MECHANIC
1,730 POSTS

This sounds like either an ignition related issue or the O2 sensor is bad.

What could be happening, when your engine is running rough, it's misfiring and allowing raw fuel to enter the exhaust which would coat your sensor with fuel and make your computer trip a code.

Or, the sensor fails intermittently and your computer can no longer calibrate that bank of the engine correctly. Then when the sensor kicks back on, the computer gets the information it needs and the idle smooths out.

At idle, while your engine is running rough, perform a cylinder drop test by pulling the plug one cylinder at a time. If the r.P.M.S drop noticeably, then that cylinder was firing correctly. If not, then that cylinder was dead. (An ignition related issue)

If all of your cylinders were firing, then check that O2 sensor for failure.

Finally, this could possibly be a fuel related issue. But usually a fuel related issue would not allow your engine to run better as r.P.M.S increase, but just the opposite.