Need help...codes
Thread Starter
Junior Member
Joined: Oct 2005
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Need help...codes
i still have the P0171 and P0507 codes. Saying system bank 1 running too lean. I have checked everywhere for vacuum leaks....can't find anything. My car is idling very rough and hesitating. What is going on here???
AudiWorld Expert
Joined: Jun 2000
Posts: 29,356
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Some good info here-
-<ul><li><a href="http://search.audiworld.com/?q=P0171&u=&s=all&cat=010022&db=19 99-01-01&de=2008-03-31">http://search.audiworld.com/?q=P0171&u=&s=all&cat=010022&db=19 99-01-01&de=2008-03-31</a</li></ul>
AudiWorld Super User
Joined: Oct 2005
Posts: 6,127
Likes: 3
The lean mixture codes, with the rough idle, and hesitating. is consistant with ...
a vac leak somewhere.
Just because you have not found the source, doesn't mean is does not exist. In this case, the leak "false air" flow is highest at idle, when manifold vacuum is highest. (absolute manifold pressure is lowest,) and is effecting the fuel mixture the most. As throttle opening angle increases, manifold vac decreases, the leak false air flow decreases, and effects the fuel mixture less, as load increases. Focus on the system hoses and connections to the manifold AFTER the throttle valve.
Less likely, is low fuel pressure at the injector rail. Check to confirm. Also, try disconnecting the MAF meter and start the engine and see if the rough idle improves, if it does, the MAF is probably bad.
Just because you have not found the source, doesn't mean is does not exist. In this case, the leak "false air" flow is highest at idle, when manifold vacuum is highest. (absolute manifold pressure is lowest,) and is effecting the fuel mixture the most. As throttle opening angle increases, manifold vac decreases, the leak false air flow decreases, and effects the fuel mixture less, as load increases. Focus on the system hoses and connections to the manifold AFTER the throttle valve.
Less likely, is low fuel pressure at the injector rail. Check to confirm. Also, try disconnecting the MAF meter and start the engine and see if the rough idle improves, if it does, the MAF is probably bad.
