Hi guys and gals.....my other thread on smog compliance help was getting old so starting fresh with a new one here.
As many of you know, I was fighting lean codes (especially 0174) and tring to get past it to get a smog check for california. Last Sunday, I was able to get the vehicle to pass a smog check by basically repetitive drive cycles and obd scans until I miraculously got it to no codes and only evap and comp monitors incomplete. Hooray!
I did not claim to have fixed the problem and it has now progressed to very rough cold idle that smooths out warm, but is still there in gear at a stop light. 0174 popping up again.
I can not find a vacuum leak. question.....when I changed the plugs and coils a couple months ago, the factory coils were denso 009700-0620. Using Rockauto reference guide,, I purchased and installed Standard Motor Product coil UF435. Can anyone tell me if the use of a product other than exact factory coil would cause a premature failure or inefficient operation, or if the UF 435 has been used by others. Ltft's at +8 this morning cold at idle, went down to almost 0 after warm up and drive around the block.

 

Just like some aftermarket MAF sensors have caused problems in these cars, so have some aftermarket coils. Coil quality varies greatly, and the Chinese-made versions are probably the worst. Jaguar struggled with their S-Type coil suppliers throughout the early 2000s until they finally seemed to get it right for the 2004 / 2005 models. Many problems caused by aftermarket coils have been reported here on the forum....