I installed a K&N CAI and now my truck flags the MAF and runs like crap. I checked and double checked for air leaks and have none. I put the stock air box assy back on and thr truck runs fine. I tried the K&N system again with the same results. Anyone else had this happen?

 

Did you disconnect the battery for a while so the computer would re-set and relearn your idle and cruise mode? You should.

 

Hey Lorenz. I've heard of people having similar issues with their MAF after a CAI install and some were resolved by TG02Z71's suggestion. I'm sure you checked this but were all the wires still hooked to the MAF? Did any of the filter oil get on the MAF? I'm stumped otherwise.
Chris

 

I reset the pcm and even tried to fix it in the tune with no luck. With the CAI installed the truck just keeps flagging the MAF. I went back to stock and drove it around all day with no problems.

 

Thats wierd, usually when that happens it's because the MAF is coated in oil from the air filter, but since it runs fine when put back to stock, I guess you could rule that out. Is it possible that since the CAI slightly relocates the MAF, the harness/connector is getting pulled and losing connection? Or maybe the filter is damaged or over-oiled and now flowing properly?