Quote Originally Posted by slater View Post
i scanned the car last night and got these codes:

2793/84 - O2-sensor before KAT Bank 1: lines
2794/84 - O2-sensor before KAT Bank 2: lines
28DD/84 - Air mass system
I had MAF issues a few months back. Mine was showing lean banks 1+2 as well as Air Mass System.
One thing you could do to try to diagnose a bad MAF would be to unplug it. You'll get a SES light, but do some accelerations full throttle. You'll find that it runs like a bat out of hell. You'll get terrible gas mileage, but at least you'll be able to rule other things out. Do this if you experience the hesitation again.

If the hesitation is present, unplug the MAF. If the problem goes away, your MAF is bad. In my case, I didn't have severe performance issues, but a new MAF resolved my lean codes. A bad bad can cause a variety of other codes to come up as well, just like my lean codes.