Engine codes I have codes PO171 & PO300 - PO304. I've already replaced air and fuel filers, O2 sensor, purge valvue, maf sensor and see no vacum line leeks. What's left?

Marvin

• 85242 Answers
• Posted on Sep 16, 2008

SOURCE: 2001 Jetta 1.8T 172 engine code

You may just have a dirty MAF sensor, spray brake clean through the sensor and clear the code, run it a few days to see if the code comes back.

SOURCE: 97 jetta won't start when engine is cold

It sounds like your starter motor could be at fault.

Does it turn over slowly,or not at all with out the jum leads?

SOURCE: MKIV VW GTI FUEL PROBLEM

Check all vacume lines for cracks. Throttle body cleaning.

SOURCE: 01247 fault code vw vr6

throttle may need adapted

SOURCE: p0171 lean code will not go away. changed fuel

Double check the very small hose that comes off of the manifold, since it sits so close to the manifold, I would not be surprised to find it frail and broken.

If you have tried everything else, have you had the code cleared after you changed out the parts? try having it cleared again....