I recently purchased and installed a non AC CT supercharger on my AP1, after a couple of weeks of trial and error I finally figured out why my car was running lean. My set up was H/TP/E. I removed my test pipe and exchanged it with my stock cat, my AFR are now dead on 12.0-12.5 with no issues. I also did a direct wire of my fuel pump JIC. Thanks for your help guys. Happy boosting.

 

did you try turning up the fuel pressure?

 

I tried using an AEM FPR with a 12:1 FMU and I had the FPR turned all the way up and I still ran lean. I also tried a comptech FPR with no luck. After replacing the test pipe with a cat the AFR's were dead on.

 

sounds spot on

 

Where/how did u read afr?

 

i used my aem wideband and a sniffer on dyno