I just put in an Air/fuel gauge and am curious if it is common for it to sweep continuously from lean to rich during driving and idle. I have a B18 with raised compression and timing gears set 2 degrees opposite of each other. Also, when I'm driving alittle hard, I can feel the car suddenly get more power and I notice that the gauge then says i"m running rich during that power band. Is that common also?

 

It sweeps back and forth because it's hooked up to the stock narrowband sensor, which is about worthless for telling how the engine is running at anything other than 14.7:1. It swings back and forth at idle because the ecu uses the sensor to hover around 14.7:1, so it hits on 14.6 and 14.8, causing the o2 sensor to read rich and lean. It can't tell how rich or how lean, however. If your gauge ever reads lean when you're getting on it, you've got problems, because it's WAY lean by the time that thing tells you about it. It sounds like you need the car tuned.

 

So for now its fine as long as its not lean while i'm getting in it, right? I'm trying to save alittle money to get my ecu programmed and to get some dyno time.

 

Hovering back and forth while cruising is fine, that's what it should do. But past about 1/2 throttle it should go rich and stay there. It should never go lean under WOT.