Exhaust is fine.. don't worry about it unless you seriously hear it.
Maf.. be careful. it's better to get an stocker from a JY than a reman. For some reason our cars are very fussy on MAF's. I know...cheap is actually better in this case..lol

I'm talking the cables and wire themselves. Might be the issue...but it's more common on the power hog Bonneville.