I recently purchased a 95 Camaro Z28 from my sister, She had a misfire with the engine just before selling. Seems to run rough, no power, car spits and sputters, Black sut comming out exhaust, and service enginge soon light on. She had new opti, plugs, and wires installed with no resolve. She then took to a shop and had it hooked up to a computer, they checked the codes and replaced the left O2 sensor. Car ran fine for 700 miles and now im having the same problem. I have checked the fuel pressure and there is no problem there, unhooked the MAF sensor and it still does it. Plug wires look fine. Any ideas???

 

Get the car scanned again & see wht codes they come up with. may be that the right O2 sensor went bad. What grade fuel are u using?

 

the cat could be plugged up

 

I'm using premium. I will have it scaned and let you know what was found.

 

Codes were left O2 sensor again, Cat was clogged causing left O2 sensor to clog up with carbon. I think the reason it only clogged the left one is that on a stock pipe the left side is 3 times more restrickted than the right due to the right side slopes down to the cat and the left side slopes down with 2 90's before it reaches the cat so the right side being less restricted was able to breath better. Almost 2 times more power with cat open and good O2 sensors.