When I first got my 2007 Mazda 3i the engine light was on, I work on the engine till I got the light to go out. After that the 2.0 liter engine pulled hard from 0 to 45 mph in normal driving. In the last two or three weeks it's been pulling hard from 0 to 70 in normal driving. The only high performance parts I've put on the engine are a gte stage one chip and a k&n replacement filter. I know neither one of them has given the engine that kind of power to make the difference in the pull in mph. I do not understand what's going on. I hope one of you can help me to understand.

 

When I couldn't get an answer I went and talked to one of the mechanics at the Mazda place in town. He told me the swirl flaps in the intake manifold more than likely got suck in the closed position and that was why my Mazda 3i didn't pull hard past 45 mph in normal driving. He also told me the reason more than likely the Mazda 3i pulls hard to 70 mph is the swirl flaps broke loos and their working right now.