Ok. My Fuel Pressure is set at 48psi. Noticeably higher than the Stock psi.

My VAFC is leaned out throughout the powerband. Not by alot, but by 5% or so. Depends where the RPM is.

Anyways, occasionally I get a CEL light for running too Rich or Lean. Not sure which one it is.


Would you guys think I'm running too Lean or too Rich?

 

Have you had the car dynoed? I own a '99 Si with the usual boltons(i/h/e/fpr/etc.) and I have my pressure set at 40psi and have my VAFC leaned out about 2%, This was done on the dyno by the technician. They showed me where I was running lean and made some adjustments. I also picked up quite a few ponies between 4600 and 7000. Also check to make sure you don't have a bad o2 sensor. Since doing my mods(only about 1 year ago) I have replaced both o2 sensors.

 

so if the o2 sensor is bad, it can trigger the car to throw a CEL light?

 

Yes. Bad o2 sensors will definitely trigger a CEL. I know I've been down this road.