Originally Posted by Speedy

I'd say your service manager is correct. These cars are MAF based, which reads air flow and adds fueling to what it sees from those readings. I doubt mild bolt ons like a CBE and CAI will flow enough air over stock to get the MAF out of the range of adjustment it can command from the PCM.

Has anyone actually ran AFR numbers on a car before and after to see how much the AFR changed with a CBE, CAI, or combination of the two? Surely someone has. On my Challenger, exhaust and intake didn't change the AFR at all, and it's MAP based and has no way to adjust for anything on it's own like a MAF car will.

I'd wager maybe even test pipes wouldn't need a tune either. Maybe adding LT headers would finally get to a point it'd be necessary....I'd need to see some data from the other bolt ons to speak to that.

My 4Runner is MAF based, and it adjusted just fine with no tune when I slapped a supercharger on it AFR wise at 7psi of boost. However, I did have to add a piggy back controller to manipulate timing, then I upped the boost to 10psi and then had to tune it, which I did myself.