I have A/F ratio guages installed on the front and rear O2 sensors on my '96 SE. On the way to work this morning, I noticed my rear one was running lean while the front one stayed in the stoich area. I was coming up a slight incline at about 3/4 throttle. The car didn't downshift so it was lugging a little bit, but it was still accelerating pretty good. It ran this way for about a mile before the car got up to speed and the guages went back to bouncing back and forth. Is this a problem?

 

It may be the beginning signs of a O2 sensor on it's way out. It's my understanding that the rear bank sensor is usually the one that fails. I also think that having aftermarket Y-pipe inherintly make our cars run a little leaner than normal. What were your rpms at when you noticed this problem. Were they traveling thru the 2800-4000rpm range at the time?


Dave

 

That crossed my mind. I don't recall exactly what my rpm's were at the time. If I had to venture a guess, I'd say it was somewhere in that range. I had just taken a right turn and hit it so I was still up in the rpm's. I think maybe if I'd have made it downshift it would've gone rich. I just had all the O2's changed under the recall about a year ago. Do you think it'd go bad this soon?