On a cold morning i go to warm my car up. It turns on like normal and goes all the way rich. A few seconds later the lights on my Autometer AF gauge slowly starts to climb down till there's no LEDs lit up. While it's idling it will surge every once and a while to say 1400 rpm and drop back down to 900-1100. Driving off the the guage slowly climbs up till it starts bouncing like normal. It sometimes surges when its fully warmed up. Today it acted up at startup. But after warmed up it didn't do it. What the hell is going on?

 

the o2 sensor has a heater on it, they don't work very well for a couple minutes after a cold startup.. mine basicly always reads 0 volts, that and the colder air density cause the ecu to run extra rich while its cold

 

Yeah but mine is running lean...

 

My gauge starts buried in rich on a cold morning,then it slowly goes across the gauge to lean then starts jumping around like normal.Don't know if that helped at all.

 

thats ok, the sensor isn't accurate until its warmed up