A common 2.5L issue for a lean code, dying problem; is the pvc diaphragm, which typically fails, causing a vacuum leak.
The diaphragm can be replaced; rather, then the whole valve cover.
re: 2.5L PCV valve failure solutions from Dorman! The 2.5L; has a common issue, where the PCV valve fails. Up until now the only option; was to buy a whole new valve cover from Volkswagen (VW doesn't sell the PCV separately); at $225 or more, plus install... it is a pretty expensive fix with...
www.newbeetle.org
We have seen vacuum leaks from a plug in the head, bad maf sensors and weak fuel pumps.
I am new to this forum but leveraged the knowledge here to help me attempt to troubleshoot an issue with my daughter's 2006 beetle. The only problem is that none of the solutions I found were the fix for the problem the car was having. I don't generally post on forums very often but, I am...
www.newbeetle.org
So, there are a number of things to check and test. You may have multiple issues going on, causing all these trouble codes, lean fuel trim , stalling, misfires, etc., and a process of elimination, should help you narrow down the problem(s).
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