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P0171 Diagnostic Trouble Code Discussion for April 2009

Fuel System Lean (Bank 1)


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Trouble Ticket Help Requests for DTC P0171
Help Request Posted
2001 BMW 525i 2.5L MIL Lamp on VIN: WBADS43451
P0171: System too lean Bank1. Hi, fellow techs, I need some help on this 525i wagon.The vehicle came in with multiple codes.I have replaced B2 S1 O2 sensor and broken PCV hose from crankcase vent valve to oil dip stick tube to fix lean codes and O2 heater code.Now,I have a problem checking...
April 02, 2009
1999 Ford E-250 Econoline 5.4L Poor Idle Quality, MIL Lamp on, p0171 VIN: 1FTPS24L8X
P0171: lean bank one. if any tech out there could help it would be greatly appreciated. van is running lean bank one, fuel trim is 25% one and -1% bank 2, with a lean shake at idle but no hard missfire. smoked engine several times warm and cold, no leaks found. baro is sitting at 1...
April 03, 2009
2000 Toyota Echo 1.5L Poor Idle Quality, Stall, MIL Lamp on VIN: JTDBT1236Y
P0171: Fuel System Too Lean (Bank 1). This car came in with a stall at idle when cold. I found the VVT valve broken so I replaced it. I checked Base Timing and it is o.k. These codes came back and it won't idle cold. Any help with this would be greatly appriciated. Mike
April 03, 2009
2001 BMW 325Ci 2.5L MIL Lamp on VIN: WBABS33471
P0171: Lean limit bank one Mult at 12. This vehicle is a dealer failed attempt to diagnose and fix. They had this car for over three months and no luck at all. When I got the car, the customer said to keep it until it is fixed. I told her that will fix it. The dealer "said" they had enginee...
April 07, 2009
1999 Ford Explorer Sport 4.0L MIL Lamp on VIN: 1FMYU24E4X
P0171: lean bank 1. ... perfectly codes keep coming back,stft1.56 bank1,stft-0.78 bank2,ltft24.96 bank1,ltft24.18bank2 [...] patterns are good.no vacume leaks found my questin is should not the fuel pressure rise under accell,mitchel gives 35 to 65 psi rather a wide range. the sy...
April 08, 2009
2001 Infiniti I30 3.0L Poor Idle Quality, Cuts out, Stall VIN: JNKCA31A41
P0171: Fuel Trim Lean (Bank 1). Thanks in advance for all who reply. This car came in for a belt noise, Put a new tensioner and fixed noise. But found on test drive that car had no power, also pops back through intake. Car will barely run when it is cold but when it warms up will stay idlein...
April 08, 2009
1999 Lexus ES300 3.0L Poor Idle Quality, Misfire, MIL Lamp on VIN: JT8BF28G0X
P0171: Fuel System Too Lean (Bank 1). Hello everyone! I have this vehicle and need an advice. It came in running rough with engine pinging and tapping a little .I believe there is two separate problems and I'd like to isolate them separetly. Tested Knock Sensors with labscope . Seems like I get ri...
April 08, 2009
2000 Oldsmobile Alero GX 2.4L Poor Idle Quality VIN: 1G3NK52T4Y
P0171: Fuel System Lean. need help guys, i have a 2000 old alero that we replaced the water pump timing belt, guides and tensioner. now after the test drive only at idle at a stop there is a rough idel like the car is missfireing, all other speed run great. fault po171 is the only fa...
April 08, 2009
1999 Ford Windstar LX 3.8L MIL Lamp on VIN: 2FMZA514XX
P0171: lean condition bank 1. well hello there guys.we have a 1999 ford windstar 3.8l with 135 k.the complaint has always been lean condition on both banks po171 po174..data shows ltft 33%stft25% almost identical on scan tool for both banks.baro is 158hz 99kpa ,we've replaced a new fuel pu...
April 09, 2009
2002 Dodge Dakota Sport 3.9L Hesitation, MIL Lamp on VIN: 1B7HG38X32
P0171: Fuel System Lean (Bank 1). Hello, this is returnless system and no fuel filter. where is the pressure regulator? Other than fpump anything else can cause low pressure? thanks, Rick
April 10, 2009
2000 Ford E-150 Econoline 4.2L Poor Idle Quality, MIL Lamp on VIN: 1FTRE1421Y
P0171: system lean. I have this e150 that came in sputtering and barely idling with a check engine light on. Off idle engine smooths out.I ran a smoke test as a bad pcv elbow has caused this sympton many times.I found no leak but replaced a weathered hose anyway. A little researc...
April 10, 2009
2006 Volkswagen Passat 2.0T 2.0L MIL Lamp on VIN: WVWEK73C46
P0171: lean code. Hi People of the Wrench, I have a VW here that displays signs of an intake leak. On the road you would never know there is anything wrong outside of an occaisional stutter at idle. Acceleration is crisp, smooth and doesn't display any evidence of a boost leak...
April 10, 2009
1999 Ford Windstar LX 3.8L MIL Lamp on VIN: 2FMZA514XX
P0171: lean condition bank 1. well hello there guys.we have a 1999 ford windstar 3.8l with 135 k.the complaint has always been lean condition on both banks po171 po174..data shows ltft 33%stft25% almost identical on scan tool for both banks.baro is 158hz 99kpa ,we've replaced a new fuel pu...
April 14, 2009
2005 Toyota Tacoma Pre Runner 4.0L Hesitation, Cuts out, Stall VIN: 3TMKU72N15
P0171: Fuel System Too Lean (Bank 1). after replacing maf truck ran good for 1/4 mile.at wide open throttle it falls on its face.it will idle all day,but in park if you hold it wide open it will fall from 5000 rpm to 0 and die.no other codes found.it does it all the time.a/f sensors appear ok.
April 14, 2009
1999 Ford E-250 Econoline 5.4L Poor Idle Quality, MIL Lamp on, p0171 VIN: 1FTPS24L8X
P0171: lean bank one. if any tech out there could help it would be greatly appreciated. van is running lean bank one, fuel trim is 25% one and -1% bank 2, with a lean shake at idle but no hard missfire. smoked engine several times warm and cold, no leaks found. baro is sitting at 1...
April 15, 2009
2001 Infiniti QX4 3.5L Poor Idle Quality, MIL Lamp on, interm lack of power VIN: JNRDR09Y51
P0171: Fuel Trim Lean (Bank 1). this vehicles been thru a few people, the trouble codes take a few days to return, but do return every time they are cleared. working thru trouble tree and currently checking wiring, buti am looking more toward the mechanical side to find this issue. idles sli...
April 15, 2009
2000 Mercury Cougar 2.0L MIL Lamp on VIN: 1ZWFT60324
P0171: system too lean. ... flow sensors and also o2 sensors pre and post cat.we have tried to find vacuum leaks with our smoke machine with no luck. every time we fix something on this car it is good for a couple of weeks before the light comes back on with the same code p0171.
April 15, 2009
2004 Chevrolet Trailblazer EXT LT 4.2L Hesitation, Poor Fuel Economy, No Power VIN: 1GNET16S34
P0171: Fuel System Lean (Bank 1). ... thats giving me fits. Came in with a complaint of no power. Test drove and verified. Engine won't rev past 4500rpm in any gear. will run interstate speeds if you give it enough time. Pulled code and found P0014. Found inf...
April 16, 2009
2000 Mercury Cougar 2.0L MIL Lamp on VIN: 1ZWFT60324
P0171: system too lean. ... flow sensors and also o2 sensors pre and post cat.we have tried to find vacuum leaks with our smoke machine with no luck. every time we fix something on this car it is good for a couple of weeks before the light comes back on with the same code p0171.
April 16, 2009
2000 Chevrolet Silverado 1500 4.3L Hesitation, Surge, Cuts out, MIL Lamp on VIN: 1GCEC14WXY
P0171: Fuel Trim System Lean (Bank 1). ... customers sons got a DUI under age about a year ago. His license was suspended and the truck sat til about a month ago. On the second day of driving, customer notices a loud knocking noise from the engine, so he had it towed in. First thing i noticed is th...
April 20, 2009
2005 Audi A4 Quattro 2.0L Poor Idle Quality, MIL Lamp on VIN: WAUDF68E45
P0171: lean bank 1. Think that i have the po171 code fixed but idle still want to hunt only in park or nuetral(po507). Drove 25 miles and no codes . Idle will go up to 1500rpm then drop down to 750rpm then repeats. Short term fuel trim jumps to +25 when idle goes up and drops to ...
April 21, 2009
2004 Chevrolet Express 3500 6.0L Poor Idle Quality, MIL Lamp on VIN: 1GBJG31U54
P0171: Fuel Trim System Lean (Bank 1). van will sometimes idle low or stall at idle, usually in gear. I can not control the iac with scanner but I can control it with a separate controller hook up to the iac. has anyone run into this problem and can tell me if it's a wiring problem or something els...
April 21, 2009
1998 Ford Windstar GL 3.8L MIL Lamp on, lean VIN: 2FMZA5147W
P0171: lean bank one. ... IMRC inop. Found both actuators to be bad, replaced them and the intake upper and lower gaskets. thought we had it but it is back after a month with P0171. This seems to occur ONLY at idle when the engine will consistenetly add 7% more fuel to bank one tha...
April 21, 2009
1997 Lincoln Continental Spinmaker Edition 4.6L Poor Idle Quality, Surge, Cuts out, Stall, MIL Lamp on VIN: 1LNLM97V1V
P0171: Lean Bank 1. ... MIL light was on with lean codes (P0171, P0174), egr flow codes (p1408), ect code(P1116), HO2S code(P1127). Tested egr and flow-ok, ect tested ok, MAF signal looks good with no drop outs. LTFT on both banks is 25! STFT o...
April 21, 2009
2000 Ford Explorer XLS 4.0L Poor Idle Quality, Stall, Misfire, MIL Lamp on VIN: 1FMYU60E3U
P0171: fuel system lean bank1. i have aquired this 2000 for explorer sport from another mechanic that has replaced most basic items to attempt to repair the stalling and misfire issue, the girl that drives this vehicle is in medical school and she can never drop the vehicle off for more tha...
April 24, 2009
1998 Ford Windstar GL 3.8L MIL Lamp on, lean VIN: 2FMZA5147W
P0171: lean bank one. ... IMRC inop. Found both actuators to be bad, replaced them and the intake upper and lower gaskets. thought we had it but it is back after a month with P0171. This seems to occur ONLY at idle when the engine will consistenetly add 7% more fuel to bank one tha...
April 25, 2009
2000 Chevrolet Silverado 1500 4.3L Hesitation, Surge, Cuts out, MIL Lamp on VIN: 1GCEC14WXY
P0171: Fuel Trim System Lean (Bank 1). ... customers sons got a DUI under age about a year ago. His license was suspended and the truck sat til about a month ago. On the second day of driving, customer notices a loud knocking noise from the engine, so he had it towed in. First thing i noticed is th...
April 27, 2009
2005 Ford F-150 XL 4.2L MIL Lamp on VIN: 2FTRF17294
P0171: system too lean bank 1. hello everybody, i just wanted to say thank you for all the help with this one. it started around 6 weeks ago. came in with the above listed codes i smoked the upper and lower intakes-no problem found. fuel filter appeared o.e. i replaced it, test drove-light...
April 27, 2009
2000 Jaguar S-Type 3.0L Poor Idle Quality, Cuts out VIN: SAJDA01C8Y
P0171: System lean Bank 1. There were 4 DTCs stored and the CEL was on, which the customer hadn't mentioned when he made the appt. I read the codes, which I have listed above. I found the #6 plug encrusted with brownish carbon while the other 2 left bank plugs were normal. The right ban...
April 27, 2009
2001 Ford F-450 Super Duty XL 6.8L MIL Lamp on VIN: 1FCNF53S4Y
P0171: lean bank one. Replace fuel pump last week, low fuel pressure 25 psi, 34-36 at rpm. Drive 20 -30 miles lean codes come back, long term reaches 12% and will go into drive open loop, under 6% load. above that will go into close loop. Checked for vac leaks with smoke , no leaks...
April 29, 2009
2001 BMW 525i 2.5L MIL Lamp on VIN: WBADS43451
P0171: System too lean Bank1. Hi, fellow techs, I need some help on this 525i wagon.The vehicle came in with multiple codes.I have replaced B2 S1 O2 sensor and broken PCV hose from crankcase vent valve to oil dip stick tube to fix lean codes and O2 heater code.Now,I have a problem checking...
April 02, 2009
1999 Ford E-250 Econoline 5.4L Poor Idle Quality, MIL Lamp on, p0171 VIN: 1FTPS24L8X
P0171: lean bank one. if any tech out there could help it would be greatly appreciated. van is running lean bank one, fuel trim is 25% one and -1% bank 2, with a lean shake at idle but no hard missfire. smoked engine several times warm and cold, no leaks found. baro is sitting at 1...
April 03, 2009
2000 Toyota Echo 1.5L Poor Idle Quality, Stall, MIL Lamp on VIN: JTDBT1236Y
P0171: Fuel System Too Lean (Bank 1). This car came in with a stall at idle when cold. I found the VVT valve broken so I replaced it. I checked Base Timing and it is o.k. These codes came back and it won't idle cold. Any help with this would be greatly appriciated. Mike
April 03, 2009
2001 BMW 325Ci 2.5L MIL Lamp on VIN: WBABS33471
P0171: Lean limit bank one Mult at 12. This vehicle is a dealer failed attempt to diagnose and fix. They had this car for over three months and no luck at all. When I got the car, the customer said to keep it until it is fixed. I told her that will fix it. The dealer "said" they had enginee...
April 07, 2009
1999 Ford Explorer Sport 4.0L MIL Lamp on VIN: 1FMYU24E4X
P0171: lean bank 1. ... perfectly codes keep coming back,stft1.56 bank1,stft-0.78 bank2,ltft24.96 bank1,ltft24.18bank2 [...] patterns are good.no vacume leaks found my questin is should not the fuel pressure rise under accell,mitchel gives 35 to 65 psi rather a wide range. the sy...
April 08, 2009
2001 Infiniti I30 3.0L Poor Idle Quality, Cuts out, Stall VIN: JNKCA31A41
P0171: Fuel Trim Lean (Bank 1). Thanks in advance for all who reply. This car came in for a belt noise, Put a new tensioner and fixed noise. But found on test drive that car had no power, also pops back through intake. Car will barely run when it is cold but when it warms up will stay idlein...
April 08, 2009
1999 Lexus ES300 3.0L Poor Idle Quality, Misfire, MIL Lamp on VIN: JT8BF28G0X
P0171: Fuel System Too Lean (Bank 1). Hello everyone! I have this vehicle and need an advice. It came in running rough with engine pinging and tapping a little .I believe there is two separate problems and I'd like to isolate them separetly. Tested Knock Sensors with labscope . Seems like I get ri...
April 08, 2009
2000 Oldsmobile Alero GX 2.4L Poor Idle Quality VIN: 1G3NK52T4Y
P0171: Fuel System Lean. need help guys, i have a 2000 old alero that we replaced the water pump timing belt, guides and tensioner. now after the test drive only at idle at a stop there is a rough idel like the car is missfireing, all other speed run great. fault po171 is the only fa...
April 08, 2009
1999 Ford Windstar LX 3.8L MIL Lamp on VIN: 2FMZA514XX
P0171: lean condition bank 1. well hello there guys.we have a 1999 ford windstar 3.8l with 135 k.the complaint has always been lean condition on both banks po171 po174..data shows ltft 33%stft25% almost identical on scan tool for both banks.baro is 158hz 99kpa ,we've replaced a new fuel pu...
April 09, 2009
2002 Dodge Dakota Sport 3.9L Hesitation, MIL Lamp on VIN: 1B7HG38X32
P0171: Fuel System Lean (Bank 1). Hello, this is returnless system and no fuel filter. where is the pressure regulator? Other than fpump anything else can cause low pressure? thanks, Rick
April 10, 2009
2000 Ford E-150 Econoline 4.2L Poor Idle Quality, MIL Lamp on VIN: 1FTRE1421Y
P0171: system lean. I have this e150 that came in sputtering and barely idling with a check engine light on. Off idle engine smooths out.I ran a smoke test as a bad pcv elbow has caused this sympton many times.I found no leak but replaced a weathered hose anyway. A little researc...
April 10, 2009
2006 Volkswagen Passat 2.0T 2.0L MIL Lamp on VIN: WVWEK73C46
P0171: lean code. Hi People of the Wrench, I have a VW here that displays signs of an intake leak. On the road you would never know there is anything wrong outside of an occaisional stutter at idle. Acceleration is crisp, smooth and doesn't display any evidence of a boost leak...
April 10, 2009
1999 Ford Windstar LX 3.8L MIL Lamp on VIN: 2FMZA514XX
P0171: lean condition bank 1. well hello there guys.we have a 1999 ford windstar 3.8l with 135 k.the complaint has always been lean condition on both banks po171 po174..data shows ltft 33%stft25% almost identical on scan tool for both banks.baro is 158hz 99kpa ,we've replaced a new fuel pu...
April 14, 2009
2005 Toyota Tacoma Pre Runner 4.0L Hesitation, Cuts out, Stall VIN: 3TMKU72N15
P0171: Fuel System Too Lean (Bank 1). after replacing maf truck ran good for 1/4 mile.at wide open throttle it falls on its face.it will idle all day,but in park if you hold it wide open it will fall from 5000 rpm to 0 and die.no other codes found.it does it all the time.a/f sensors appear ok.
April 14, 2009
1999 Ford E-250 Econoline 5.4L Poor Idle Quality, MIL Lamp on, p0171 VIN: 1FTPS24L8X
P0171: lean bank one. if any tech out there could help it would be greatly appreciated. van is running lean bank one, fuel trim is 25% one and -1% bank 2, with a lean shake at idle but no hard missfire. smoked engine several times warm and cold, no leaks found. baro is sitting at 1...
April 15, 2009
2001 Infiniti QX4 3.5L Poor Idle Quality, MIL Lamp on, interm lack of power VIN: JNRDR09Y51
P0171: Fuel Trim Lean (Bank 1). this vehicles been thru a few people, the trouble codes take a few days to return, but do return every time they are cleared. working thru trouble tree and currently checking wiring, buti am looking more toward the mechanical side to find this issue. idles sli...
April 15, 2009
2000 Mercury Cougar 2.0L MIL Lamp on VIN: 1ZWFT60324
P0171: system too lean. ... flow sensors and also o2 sensors pre and post cat.we have tried to find vacuum leaks with our smoke machine with no luck. every time we fix something on this car it is good for a couple of weeks before the light comes back on with the same code p0171.
April 15, 2009
2004 Chevrolet Trailblazer EXT LT 4.2L Hesitation, Poor Fuel Economy, No Power VIN: 1GNET16S34
P0171: Fuel System Lean (Bank 1). ... thats giving me fits. Came in with a complaint of no power. Test drove and verified. Engine won't rev past 4500rpm in any gear. will run interstate speeds if you give it enough time. Pulled code and found P0014. Found inf...
April 16, 2009
2000 Mercury Cougar 2.0L MIL Lamp on VIN: 1ZWFT60324
P0171: system too lean. ... flow sensors and also o2 sensors pre and post cat.we have tried to find vacuum leaks with our smoke machine with no luck. every time we fix something on this car it is good for a couple of weeks before the light comes back on with the same code p0171.
April 16, 2009
2000 Chevrolet Silverado 1500 4.3L Hesitation, Surge, Cuts out, MIL Lamp on VIN: 1GCEC14WXY
P0171: Fuel Trim System Lean (Bank 1). ... customers sons got a DUI under age about a year ago. His license was suspended and the truck sat til about a month ago. On the second day of driving, customer notices a loud knocking noise from the engine, so he had it towed in. First thing i noticed is th...
April 20, 2009
2005 Audi A4 Quattro 2.0L Poor Idle Quality, MIL Lamp on VIN: WAUDF68E45
P0171: lean bank 1. Think that i have the po171 code fixed but idle still want to hunt only in park or nuetral(po507). Drove 25 miles and no codes . Idle will go up to 1500rpm then drop down to 750rpm then repeats. Short term fuel trim jumps to +25 when idle goes up and drops to ...
April 21, 2009
2004 Chevrolet Express 3500 6.0L Poor Idle Quality, MIL Lamp on VIN: 1GBJG31U54
P0171: Fuel Trim System Lean (Bank 1). van will sometimes idle low or stall at idle, usually in gear. I can not control the iac with scanner but I can control it with a separate controller hook up to the iac. has anyone run into this problem and can tell me if it's a wiring problem or something els...
April 21, 2009
1998 Ford Windstar GL 3.8L MIL Lamp on, lean VIN: 2FMZA5147W
P0171: lean bank one. ... IMRC inop. Found both actuators to be bad, replaced them and the intake upper and lower gaskets. thought we had it but it is back after a month with P0171. This seems to occur ONLY at idle when the engine will consistenetly add 7% more fuel to bank one tha...
April 21, 2009
1997 Lincoln Continental Spinmaker Edition 4.6L Poor Idle Quality, Surge, Cuts out, Stall, MIL Lamp on VIN: 1LNLM97V1V
P0171: Lean Bank 1. ... MIL light was on with lean codes (P0171, P0174), egr flow codes (p1408), ect code(P1116), HO2S code(P1127). Tested egr and flow-ok, ect tested ok, MAF signal looks good with no drop outs. LTFT on both banks is 25! STFT o...
April 21, 2009
2000 Ford Explorer XLS 4.0L Poor Idle Quality, Stall, Misfire, MIL Lamp on VIN: 1FMYU60E3U
P0171: fuel system lean bank1. i have aquired this 2000 for explorer sport from another mechanic that has replaced most basic items to attempt to repair the stalling and misfire issue, the girl that drives this vehicle is in medical school and she can never drop the vehicle off for more tha...
April 24, 2009
1998 Ford Windstar GL 3.8L MIL Lamp on, lean VIN: 2FMZA5147W
P0171: lean bank one. ... IMRC inop. Found both actuators to be bad, replaced them and the intake upper and lower gaskets. thought we had it but it is back after a month with P0171. This seems to occur ONLY at idle when the engine will consistenetly add 7% more fuel to bank one tha...
April 25, 2009
2000 Chevrolet Silverado 1500 4.3L Hesitation, Surge, Cuts out, MIL Lamp on VIN: 1GCEC14WXY
P0171: Fuel Trim System Lean (Bank 1). ... customers sons got a DUI under age about a year ago. His license was suspended and the truck sat til about a month ago. On the second day of driving, customer notices a loud knocking noise from the engine, so he had it towed in. First thing i noticed is th...
April 27, 2009
2005 Ford F-150 XL 4.2L MIL Lamp on VIN: 2FTRF17294
P0171: system too lean bank 1. hello everybody, i just wanted to say thank you for all the help with this one. it started around 6 weeks ago. came in with the above listed codes i smoked the upper and lower intakes-no problem found. fuel filter appeared o.e. i replaced it, test drove-light...
April 27, 2009
2000 Jaguar S-Type 3.0L Poor Idle Quality, Cuts out VIN: SAJDA01C8Y
P0171: System lean Bank 1. There were 4 DTCs stored and the CEL was on, which the customer hadn't mentioned when he made the appt. I read the codes, which I have listed above. I found the #6 plug encrusted with brownish carbon while the other 2 left bank plugs were normal. The right ban...
April 27, 2009
2001 Ford F-450 Super Duty XL 6.8L MIL Lamp on VIN: 1FCNF53S4Y
P0171: lean bank one. Replace fuel pump last week, low fuel pressure 25 psi, 34-36 at rpm. Drive 20 -30 miles lean codes come back, long term reaches 12% and will go into drive open loop, under 6% load. above that will go into close loop. Checked for vac leaks with smoke , no leaks...
April 29, 2009