I have a Hummer with an LBZ swapped in. I have an ECM with custom tunes but I wanted to try my hand at tuning so I bought an extra ECM and a FlashScan. I put a stock tune with VATS and EGR disabled on my second ECM. I'm getting the p0101 code. I don't see this code with my professionally tuned ECM so I suspect it is related to MAF scaling. The MAF is in a 4 inch tube. I've been searching all night and I can't find a definitive answer as to what size the MAF section is for a stock LBZ intake. Some posts say 3.5 inches, others say 4. What should my MAF table be for an LBZ with a 4 inch intake? Is there something else I should be looking at?