Ok so for the past month my car has been giving me problems. A couple weeks ago I go to leave the house and my car starts idling weird and doesn't have any power over about 2500rpms. I drag it back to the garage replace the fuel filter and runs like a dream. Well a couple days ago I decide to go into town and it starts idling weird again and has no power so I drive it home about 5 miles away put it in the garage and brings up codes for a multiple cylinder miss fire, cylinder 1 & 2 miss fire. Oh yeah and it's had a p0420 for 02 censor for about a year now. So before I start replacing a bunch of unnecessary stuff anyone have any ideas of what it could be and how to test for it?

 

You need to get your motor scanned (preferably with VAG-COM\VCDS) for any error codes logged in the ecu and post them, that will save a lot of guessing.