pmc_73

I have a 2001 A4 1.8t (/w apprx 98k). The CEL came on about 4mons ago. P0171 (system lean bank 1) this happened after running the gas tank to almost empty, I figured the fuel filter might have gotten blocked up. Since it was never changed, I did that, cleared the code. Light did not
come back on until 2 weeks ago. Same DTC. I replaced the O2 sensor (prior to the cat) and cleaned the MAF /w some CRC MAF cleaner and replaced the airclaner. The MAF +cleaner took a bunch of brown crap off, there are still little dots on the flat silver wire, it didnt clean everything off. The car seems to idle OK.

What are my next steps? disconnect the MAF, and see if it will throw the p0171? Trace all of the vacuum lines? Replace the MAF (it was replaced once before some where around 30k i think)?

I have a ODBII reader, no vag-com.


thanks..

4Driver4

Stock intake box and air filter? If no, replace MAF.

pmc_73

the air box & filter are stock. Also, if I clear the DTCs, i can drive for about a day before the CEL comes back on.