So my 91 keeps throwing 41 and 91 codes. These indicate a lean fuel mixture (or at least the computer thinks so). I checked for vacuum leaks and all seems ok (vacuum lines are pretty much all new). My fuel pressure is at 40 and I just recently replaced my o2 sensors. I also cleaned my MAF and had a thought...

The guy before me installed 24lb injectors, e303 cam, etc in the 306 crate... It still has the stock MAF on the bbk intake. Do I need to upgrade this? I am just wondering if the MAF is pegged out and more air is getting in than the computer realizes.

Also, the smog pump was eliminated and I have off road H-pipe. Is there something to look for related to the removal of this that might throw a lean code?

I'll get this car right someday.