i got code po171 system too lean bank 1, i replaced all braded vacum hoses clean maf sensor, change air filter and reset the computer. But after running 30 miles the engine leght came back on. what else is the problem with this? does the o2 sensor got to do something about this?
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2001 Audi A4 Quattro Question: code po171
Answer #1schucks from Schucks Transmission, January 27, 2011, 12:19Enthusiast
I RESENTLY HAD A CUSTOMER WITH THIS PROBLEM, CHANGE THE MAF SENSOR AND THIS WAS THE CORRECTION. THIS IS GOING TO FIX THIS PROBLEM 9 OUT OF 10 TIMES. THX JIM
ReplyHal..., January 27, 2011, 13:06Master
Who is this???
Check all the small vacuum lines on the top of the engine again. After 90K they become brittle and will cause the P0171 code. Using a smoke machine usually roots these leaks out but you can use a can of brake cleaner if you have it. Lightly spray around those lines and see if you can get the engine to react. Be cafeful!!!
Answer #3Royal Motor Sales January 27, 2011, 14:16Technician
if you have a 1.8L engine it's most likely the hoses under the manifold. I hope that helps.
ReplyHal..., January 27, 2011, 14:20Master
Thank god WorldPac started selling that hose in bulk...
Answer #4ccsmog from Contra Costa Smog and Repair, January 27, 2011, 17:31Journeyman
You might also check for manifold leaks.