jr, in my case the dealer originally said bad MAF, I replaced it. Couple days later codes came back, I had 0174 and 0172iirc. Raised hell when I went back, they actually did their job and found out it was the Air Fuel Meter Sensor. Most factory mechanics are quick to jump on MAF, because that is what they are taught to blame at the factory schools, and they will often not even bother to run proper diagnostics. Some that haven't drank the kool-aid will actually not just stop as soon as they see a K&N style filter.