I have a 1999 Audi A4 (2.8) I am looking for any possible reason to generate codes p1136 and p1138. I changed the fuel filter thinking the fuel was to "lean" beacuse of possibly dirty filter. It does run a-lot better, however codes are still popping up. I know its a possible vacum leak, but to be honest I don't really know what I'm looking at when I take off the engine cover. Any ideas where I could locate these leaks? I am also getting ready to change my MAF. PLEASE HELP!!!

 

buy a can of Carb Clean, or something similar, and just spray squirts at the seams where parts go to gether. I.E. manifold to head, block. head to block. anywhere air could be pulled into the engine passed the MAF sensor. spray some on all the vacuum line connections, stuff like that. if the engine changes sound, and should do so quite quickly.. there is your leak, if you have one.. check back if that doesnt work..

 

I will do that tommrow. I'll post results. Thanks very much!!!

 

Maf's on that engine are rare. Id bet on a vacuum leak. Spraying and checking for a change in engine idle is a great place to start.