I don't see why any of these would matter, but then again I'm not familiar with any smog laws living out here in the rust belt. I wouldn't think the maf would be a problem. You are correcting a common failure part that could easily cause emmission and driveability problems. FPR, I guess that depends who is pissed off that day, but I would have the fp set at stock pressure. I would think the larger downpipe and intercooler would make the engine run more efficient thus less emmissions.