vermontmk6

The IE does not need the treadstone as the stock maf housing has straightener built into it.

P2177 System too lean off idle, Bank 1
P2279 Intake Air System Leak
I was showing those codes with the Cobb intake with my K04. I had issues with the way the PCV return was routed. I bought a new return hose and Cobb sent me a new intake pipe that was slightly different but still had the crappy location for PCV return. Still had the codes. As much as it pained me because I like the Cobb parts I returned the Cobb intake and got a different setup that retained the stock location for PCV return and have no codes. So in my experience it was the Cobb intake.