Dare99me

I recently began having problems with my 1.8 tt. The check engine light came, i decided to Autozone to have the check engine light tested for free with their diagnostic hand held, i know it's no VAG_COM, but it would do. Before i went there I already assumed it was the Mass Air Flow sensor, being that i changed it two years ago. I have a air intake, i figured it screwed it up again. Well the test came back as a fault with the MAF, a misfire on cylinder 3. I went ahead and got a new MAF, new plugs, new coil packs, and the check engine light is still on. It also seems to run a bit rough. Not like a f_d up spark plug rough, rough but at a steady idle. The Maf seems to be working, i can tell when i get out of first gear. I checked the plugs, which were all gapped properly. More important i noticed that my exhaust seems to let out more of a blueish smoke, and a slight smell, mabey of too much fuel. I dont know whats up, I need some input. Could it be the O2 sensors or catalytic converter???? thanks . And if anyone every changed out both of their O2 sensors on a tt, how ??

TTinCT

to insure it is NOT the MAF, disconnect it and see if the car runs better...

Could be a coilpack harness that is bad too...

JohnLZ7W

Check the connections to the intake manifold, the ones underneath it are prone to tearing just from age. Also the cloth wrapped one that goes to the fuel pressure regulator is known to fail.

Dare99me

the coil pack harness gone bad?? is that a common thing, and if so it easy to replace?

DumpTTruck

You can check for leaks by squirting WD40 on connections while the engine is running.

TTinCT

lots of other easy things to do prior than that tho....i would check all my vacuum lines prior to replacing the pack harness.....