Hey guys my 03 tt fwd is still throwing a code for running lean, no CEL but still has a code for running lean, I cleaned my maf already, but I can tell its running leaner thn usual because my exhaust tip isn't nearly as black as usual n it doesn't pop/ backfire like it used to (im basically straight piped, n my tt always popped with this exhaust so im assuming it's normal) im replacing the fuel filter soon to see wht happens plus there's 75k one the stock one anyway, so any ideas?


-Rich

 

Vac, exh, and boost leaks all can cause this. Same for a bad primary o2

 

Took my a while to find my van leak last winter, there was a massive hole in a plastic assembly underneath the manifold, pain in the *** to find.

 

According tommy gauge my vac pressure is the same as always, but ill still check, also ny new downpipe relocated my o2 sensor farther downstream, but the problem started awhile after I installed it, n it ran great for tht time with the downpipe

 

What dp are you running?

 

Ebay 3" with testpipe section not sure of the brand id hve to find the receipt

 

If you are using their gaskets, that could be an issue. They are pretty bad and could be leaking already.

 

I think I did use they're gaskets I covered Thm in copper sealant though, ill check Thm tonight