I own a 2000 Z24 auto. I usually have problems with my 02 sensor (before cat) and i have to replace them every 4 or 5 months. More recently some more problems started coming up:

1) sometimes the TRAC OFF light come on while driving, and it stays on for a couple of miles.
2) when I start my engine (cold or hot) I can clearly hear a clicking noise from the cylinder closest to the passenger side, and I can hear it get louder as i accelerate.
3) when I shift to reverse I can hear a snap sound, It seams that if I let the car rest for a day or two the snap goes away for about 2 or 3 reverse shifts.


I changed the oil, coil on plugs. I found oil on the spark plug of the cylinder that is clicking, apparently the oil is leaking from the valve cover (wich has a small crack) Is there any way to stop this leak or keeping the oil from getting to the cylinder besides changing the valve cover?

Probably a ring is letting oil blow by and it is prematurely ruining your O2 sensor.

The snap maybe a mount going bad.


My wife's 2003 Ecotec 2.2 liter Sunfire:
* 2 1/4 inch in and dual 2 inch out muffler Trans Am muffler
* 2 1/4 piping to a very long 2 1/4 inch resonator
* 2 1/4 inch catalytic converter
* an AEM true cold air intake NOPI edition
* 8 gauge ground wire kit
* Toyz front strut brace
* Russell stainless steel brake lines all around.