I have a Built GSR Engine thats Turbocharged. Lately my car has been backfiring alot. When I am crusing down the freeway ( just lightly on the gas or when I take my foot off the gas and then put my foot lightly on the gas again ) my car backfires really bad. My Speedpro Engine Mgmt. looks like its been set to run a 12.7 A/F ( at this particular part of the A/F Map ) but my Greddy A/F meter says 15.8 A/F. Also, my Greddy Oil Pressure Guage seems a lot lower than usual. The Oil Pressure Guage Reads a mark of 2, when before it would read at a mark of 4 on the guage face. When the engine is warmed up and I'm idling at a stop light, the Oil Pressure Guage shows a red light ( way below where its suppose to be ). Also, when my car is idling ( whether the engine is cold or warm ) the idling is very rough. Any ideas on what I should do? Thanks for any help.

 

were you using a wideband o2 sensor to measure this? if not, your afr is probably way off and rich which explains the backfiring and rough idle. unburnt fuel gets to the hot catalyst material in the catalytic converter and boom. idle just needs to be tuned. also the cat starts to die which means even worse performance..

 

Actually I am using a Straight Pipe.

 

i have the backfire prob too. test pipe also. i cleaned off the O2 with a propane torch (heat until slightly red, no more). no more backfire "pop"

 

Cool, thanks for the info.!