50GT

Ok guys I have replaced the O2 sensor on the left side and the code went away for about a week! The check engine light flashed again yesterday so I did the Key on engine running test and this dame code 91 popped up again! I am at a loss why the computer keeps telling me I'm running lean on the left side! Why would the left side be running lean and not the right? The last thing I have done to the car is put an off-road H-pipe but that was months ago and the code did start to appear until about three weeks ago! The code did disappear after I replaced the O2 sensor for about a week. I still have not noticed any performance problems; the car is still running strong! Please if anyone has any ideas let me know! Thanks

50GT

BTW the check engine light only flashes when the car is at a steady speed, it never flashes under hard acceleration or deceleration! Thanks

50GT

"bump"

camaroeater

I would check that you have no exhaust leaks. I had one when I installed mine and had a idle issue, then it went away after I fixed it. If i were you, i would replace the other o2 sensor.