Hello,

I just finished a track day last week and on my 2 hour drive home, had an issue pop up. First off...here is my setup. Turbo car, 550 RC injectors, K-Pro, Walbro fuel pump. The car has been tuned and running perfectly for a year now.

As I left a gas station the car started to go lean when I tried to maintain a constant rpm. I can accel and decel fine, but the car slowly goes past 18:1 if I try to stay at speed. Could this be a fuel pump on it's way out? I am lost.

Thanks for your input.

 

O2 sensor? If it's failed in a way that it's telling the engine that it's running too rich, the ECU might be trying to lean it out in closed loop.

 

if the sensor slowly starts to read lean and nothing has changed i'd look to the sensor being bad or your car has developed a small exhaust leak before the sensor.

If o2 feedback is turned on in the kpro that can cause drivability issues. The kpro will try to add fuel to compensate when it's not really needed.

 

Couple of the downpipe bolts had backed out...that and I reset the battery. Problem has gone away... so far.