CODE P0171 and P0174
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2004 BMW 325i Question: what is code P0171 and P0174
Answer #1TowerAuto from Tower Automotive Repair LLC, June 08, 2012, 21:26Technician
P0171 means the Bank 1 oxygen sensor is showing a lean condition
P0174 means the Bank 2 oxygen sensor is showing a lean condition
I would inspect the PCV system and the Air intake system for leaks
Replystelidan, July 28, 2014, 11:37Rookie
I had the same problem with the SES light coming on, failing a smoke check, and then the car would not start after I filled up with gas. I took it to a station and will get a possible problem result later today. They were thinking possible fuel pump failure. could that be the problem also, or just a system leak, or cracked intake hose near the engine?
have a smoke test done to look for vac leaks but could be a bad mass air flow also
Answer #3kathleen773 July 10, 2012, 15:39Rookie
Just had the same problem with my 2004 BMW 325i. Service Engine Soon was on as well. Mechanic said everything seemed fine but then found that a hose (intake) was cracked near engine. Replace hose for$15 and $86 for the time. Runs great now. SES light off. Codes off.