Question on fault code indicating lean fuel mixture (add).
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Question on fault code indicating lean fuel mixture (add).
Fault code states a lean fuel mixture in bank 1, (add). I understand that "add" indicates a possible vacuume leak at idle. My first question is which is bank 1, and which is bank 2? I assume this means the left and right engine banks. Second, where is a good place to start looking for this possible leak?
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Joined: May 2001
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From: Noblesville, Indiana
On my car (TT coupe) the leaks were found around the >>
diverter valve. Just open the hood and check all the vac hoses. The most obvious for me was the diverter valve since I had changed it out recently and obvioulsy did not tighten the clamps enought. Hope this helps somewhat.
Also, what was the DTC? Was it 17532? What kind of car do you have? Try the link for some light reading on fuel trim.<ul><li><a href="https://forums.audiworld.com/vag/msgs/456.phtml">Fuel Trim Explained</a></li></ul>
Also, what was the DTC? Was it 17532? What kind of car do you have? Try the link for some light reading on fuel trim.<ul><li><a href="https://forums.audiworld.com/vag/msgs/456.phtml">Fuel Trim Explained</a></li></ul>
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Would help if you mention what car you drive.
I have 3.0 Quattro and at the moment is invesigationg under performance. Since I do not have my Bentley manual yet I am guessing from other posts on the forum what is measure. Sure I think that my left bank indicates 0.8 Lambda ave and Right Bank 0.2 Lambda. This leads to fuel trim of -2.3% left and -3.2% right. This is possibly caused by spark plugs being now 50'000km (of high revolution driving) old. This then means mixture is not fully burnt thus the injector time is reduced and I have less power. Anyway that is how I figure it out and handed my car in this morning at the Audi dealer to locate the "problem". I am not too optimistic because the car has no problem only performance is down about 14kW as measured on dyno and I am not sure they have much interest in finding that problem.
However if you solved you problem with that DTC you should get much improved performance because I assume at some stage the addaptive setting to make your mixture richer (possibly blocked fuel injectors) cannot solve it anymore and then the DTC is generated.
Anyway it is interesting and I really enjoy finding things with my HEX Com. Brilliant tool and for me worth every cent it cost.
However if you solved you problem with that DTC you should get much improved performance because I assume at some stage the addaptive setting to make your mixture richer (possibly blocked fuel injectors) cannot solve it anymore and then the DTC is generated.
Anyway it is interesting and I really enjoy finding things with my HEX Com. Brilliant tool and for me worth every cent it cost.
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