Lean codes P0171 P0174 need suggestions
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Lean codes P0171 P0174 need suggestions
2005 5.4L
Truck runs great but have these lean codes, No other codes. At Idle, Long term fuel trim on both banks are maxed out, short term about 5% for a total of 35%. The kicker is during acceleration, the fuel trims don't change much. I can't tell if its a vacuum leak or a fuel problem. Checked everywhere for vacuum leaks, none found. According to my scanner, relative fuel pressure is 40 psi which is normal. Stays at 40 under load.
Clean and changed MAF- no change
At this point I took it to a dealer for a diagnostics. ($200) All they did was tell me what I already know. They ruled out a vacuum leak AND a fuel delivery problem. They said the next step was to remove and inspect the intake.
Well, that's what I did, changed gaskets- inspected everything--No change
My inspection is due in June, Any suggestions
Thanks, Chris
Truck runs great but have these lean codes, No other codes. At Idle, Long term fuel trim on both banks are maxed out, short term about 5% for a total of 35%. The kicker is during acceleration, the fuel trims don't change much. I can't tell if its a vacuum leak or a fuel problem. Checked everywhere for vacuum leaks, none found. According to my scanner, relative fuel pressure is 40 psi which is normal. Stays at 40 under load.
Clean and changed MAF- no change
At this point I took it to a dealer for a diagnostics. ($200) All they did was tell me what I already know. They ruled out a vacuum leak AND a fuel delivery problem. They said the next step was to remove and inspect the intake.
Well, that's what I did, changed gaskets- inspected everything--No change
My inspection is due in June, Any suggestions
Thanks, Chris
