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P0171 Diagnostic Trouble Code Discussion for January 2010

Fuel System Lean (Bank 1)


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Trouble Ticket Help Requests for DTC P0171
Help Request Posted
2006 Chevrolet Trailblazer LS 4.2L MIL Lamp on, P0171 VIN: 1GNDT13S86
P0171: Fuel System Lean (Bank 1). ... know one can figure out. It is a 06 Trailblazer that keeps throwing a P0171 code. Whenever it feels like it. sometimes you can drive 20 miles and it sets and other times you can drive 400 miles before it sets. pulled it into the shop, i checked tsb. did fi...
January 04, 2010
2006 Chevrolet Trailblazer LS 4.2L MIL Lamp on, P0171 VIN: 1GNDT13S86
P0171: Fuel System Lean (Bank 1). ... know one can figure out. It is a 06 Trailblazer that keeps throwing a P0171 code. Whenever it feels like it. sometimes you can drive 20 miles and it sets and other times you can drive 400 miles before it sets. pulled it into the shop, i checked tsb. did fi...
January 06, 2010
2001 Toyota Highlander 3.0L Excessive Emissions, Misfire VIN: JTEHF21A91
P0171: Fuel System Too Lean (Bank 1). I've dealt with this code on Toyotas before, this engine utilizes air/fuel sensors, not o2 sensors, but what puzzles me is why the lean codes when the engine is obviously running rich? I mean it has black sooty plugs that were replaced a week ago and already h...
January 06, 2010
1998 Ford Explorer Limited 4.0L MIL Lamp on VIN: 1FMZU32E7W
P0171: Lean Bank 1. ... a Code P0171 and a P0174. The fuel pressure is good and the Air Flow Meter Tests Good. I smoked the intake system and found two vacuum leaks that were repaired. When I scaned the vehicle all the Fuel Trims Numbers (Both Short & Long) Show -100.6 % a...
January 08, 2010
2000 Ford Taurus SE 2-Valve 3.0L Poor Idle Quality, MIL Lamp on VIN: 1FAFP53U8Y
P0171: Bank 1 lean. Vehicle came in with CEL on, P0171, P0174. Customer said he replaced the PCV hose assembly because it was leaking. It was replaced and done correctly. Check for vac leaks, found none. Check MAF and baro readings w/ scan tool, everything looks good, cleaned MAF...
January 08, 2010
2000 Toyota Tundra 3.4L Cuts out, Stall, no power VIN: 5TBBT4811Y
P0171: Fuel System Too Lean (Bank 1). Truck was towed in for inoperative starter motor. Replaced starter motor with reman unit, now truck starts and will idle but as soon as we hit gas pedal it has no power and stalls. Scanner shows o2 sensors are going lean..Seems to be a fuel problem. LTFT +27%....
January 09, 2010
2000 Ford Taurus SE 2-Valve 3.0L Poor Idle Quality, MIL Lamp on VIN: 1FAFP53U8Y
P0171: Bank 1 lean. Vehicle came in with CEL on, P0171, P0174. Customer said he replaced the PCV hose assembly because it was leaking. It was replaced and done correctly. Check for vac leaks, found none. Check MAF and baro readings w/ scan tool, everything looks good, cleaned MAF...
January 11, 2010
2004 Jaguar XJ8 4.2L Misfire, MIL Lamp on VIN: SAJWA71C14
P0171: System Lean Bank 1. ... bank 1, P0301, P0303, P0305, check, for vacuum leak, made sure gaskets were good on dip stick, oil cap was tight, and Pcv gaskets good as well. found no vacuum lines loose or leaking. hooked up smoke machine to verify no ...
January 11, 2010
2004 Chevrolet Avalanche 1500 5.3L Excessive Emissions, Poor Idle Quality, Misfire, MIL Lamp on VIN: 3GNEK12T14
P0171: Fuel Trim System Lean (Bank 1). Truck is sort of intermittant but it always adds fuel to bank 1, and around 25% at idle though the pulse width looks the same as the other bank. Will sometimes run very well, next time VERY rough idle. Usually, #1 cyl will miss most, and some for #3, but now w...
January 13, 2010
2005 Chevrolet Silverado 1500 5.3L Misfire VIN: 1BGTYUII66
P0171: Fuel Trim System Lean (Bank 1). Fuel trim bank 1 is stuck at +25% WITH IGNITION ON and engine off. I have dis-connected battery and tried again, same results. STFT are at 0 on both banks. Plugs are black with soot on bank 1, beautiful on bank 2, cant find any intake leaks from the outside, ...
January 13, 2010
2000 Nissan Maxima GXE 3.0L MIL Lamp on VIN: JN1CA31A9Y
P0171: Fuel Trim Lean (Bank 1). code 171 setting mil light,no drivabilty complaints,smoke tested all intake system ,no leaks present,scoped injector patterns & all 3 02 sensors ok,injector pulse width slightly smaller on rear bank,fuel pressure & volume test all in spec,mass air flow...
January 14, 2010
1996 Ford E-150 Econoline 4.9L Poor Idle Quality, Stall, Misfire, MIL Lamp on VIN: 1FTEE14Y6T
P0171: lean bank one. ... day and had a code p0171 p0174 p0300 and p0420. we chose to go for the lean codes first in hopes they would also cure the others. found fuel trims short term maxing out nearly immediately after warm up at 33%. but when the engine is reved to 1500 rpm or mo...
January 15, 2010
2005 Ford Taurus SE 3.0L Poor Idle Quality, Surge, Melted intake VIN: 1FAFP56275
P0171: lean. This vehicle cam in with these codes a week ago. Found holes in the intake (melted) where the pcv hose goes into the upper intake. Also noted extremely hot pcv assembly hose. Checked for restricted exaust, checked ok. Replaced intake and pcv heater, and had a ...
January 15, 2010
1996 Ford E-150 Econoline 4.9L Poor Idle Quality, Stall, Misfire, MIL Lamp on VIN: 1FTEE14Y6T
P0171: lean bank one. ... day and had a code p0171 p0174 p0300 and p0420. we chose to go for the lean codes first in hopes they would also cure the others. found fuel trims short term maxing out nearly immediately after warm up at 33%. but when the engine is reved to 1500 rpm or mo...
January 18, 2010
2000 Chevrolet Cavalier Z24 2.4L Stall VIN: 1G1JF12T4Y
P0171: Fuel System Lean (Bank 1). The car runs perfectly until it reaches full operating temperature and has gone 10 to 15 km's. Stumbles once or twice then stalls as though the key has been turned off. If it sits for 15 minutes it will start up and run fine again. tested all parameters for ea...
January 19, 2010
2002 Toyota Corolla S 1.8L MIL Lamp on VIN: 1NXBR12E62
P0171: Fuel System Too Lean (Bank 1). ... code. i checked maf sensor it was only reading 1.3 g/s at idle i cant find any specs for idle but that seems low, what is normal for this engine?.maf was reading 80% calc engine load WOT at 55mph they say on identifix should be 80-85. replaced maf still se...
January 20, 2010
1999 Ford Taurus SE 3.0L Excessive Emissions, MIL Lamp on, Fuel Sytem Lean VIN: 1FAFP53SXX
P0171: Fuel System Lean Bank 1. Ok everyone this one's a killer. This car was brought by a lady who had it at another shop who could not solve this problem. Check engine light is on with bank one and two lean codes. Long term fuel trims at idle hang around 20 to 25. The second you raise the ...
January 21, 2010
2005 Land Rover LR3 SE 4.4L Excessive Emissions, Poor Idle Quality, Poor Fuel Economy, MIL Lamp on VIN: SALAA25435
P0171: lean code. ... with a mass air flow code originaly 3 months ago. fuel trims were slightly ellivated but ran good and no power issues. customer declined doing maf anyway getting good gas millage. Car back bad gas millage. Only code still maff code p0101, smoked intake had...
January 21, 2010
1999 Mercury Grand Marquis GS 4.6L MIL Lamp on VIN: 2MEFM74W5X
P0171: System too lean bank 1. Customer had no complaints other than CEL on. Ran codes and got the common 171-174 lean both banks. Did the MAF clean, check vacuum leaks, replace PCV,oem part. Checked for vacuum at crankcase with PCV plugged and no negative pressure. Cleared codes, test drov...
January 24, 2010
1996 Jeep Cherokee SE 4.0L Excessive Emissions, MIL Lamp on VIN: 1J4FJ28SXT
P0171: Fuel System Lean (Bank 1). Vehicle brought into shop with check engine light on , found o2 sensor no voltage. replaced o2 sensor everything worked fine for about 15 minutes. o2 sensor voltage with koeo reads 0.00 volts, if you watch scan data for about 5 minutes voltage will eventuall...
January 25, 2010
2000 Ford Explorer Eddie Bauer 5.0L MIL Lamp on VIN: 1FMZU84P1Y
P0171: fuel system too lean bank 1. ... explorer came in to me with the service engine soon light on which had been on for nearly a year. It is time for mass state inspection so it was time that he finally had to get it fixed. I scaned for codes and found p0171 and...
January 26, 2010
2002 Toyota Corolla S 1.8L MIL Lamp on VIN: 1NXBR12E62
P0171: Fuel System Too Lean (Bank 1). ... code. i checked maf sensor it was only reading 1.3 g/s at idle i cant find any specs for idle but that seems low, what is normal for this engine?.maf was reading 80% calc engine load WOT at 55mph they say on identifix should be 80-85. replaced maf still se...
January 26, 2010
2000 Ford Explorer Eddie Bauer 5.0L MIL Lamp on VIN: 1FMZU84P1Y
P0171: fuel system too lean bank 1. ... explorer came in to me with the service engine soon light on which had been on for nearly a year. It is time for mass state inspection so it was time that he finally had to get it fixed. I scaned for codes and found p0171 and...
January 27, 2010
2000 GMC 3500HD 7.4L Misfire VIN: 1GDKC34J5Y
P0171: testing and results. Engine idles fine and will rev fine if you give it just a little throttle. Try to give it a heavy throttle and the engine starts missing, if the throttle is held steady at any RPM the engine runs smooth with no miss but as soon as you try to give it some throt...
January 27, 2010
2004 Jaguar X-Type 3.0L MIL Lamp on VIN: SAJEA51C84
P0171: Lean Condition - Bank 1. ... codes P0171 & P0174. off idle fuel trims are normal. at idle in park lt fuel trims are both at 18%, idle in drive 19.5%. car idles beautifully and vacuum is 20.5". MAP reads 8.9" - 9.2" (we are just barely ...
January 28, 2010
2004 Jaguar X-Type 3.0L MIL Lamp on VIN: SAJEA51C84
P0171: Lean Condition - Bank 1. ... codes P0171 & P0174. off idle fuel trims are normal. at idle in park lt fuel trims are both at 18%, idle in drive 19.5%. car idles beautifully and vacuum is 20.5". MAP reads 8.9" - 9.2" (we are just barely ...
January 29, 2010
2006 Chevrolet Trailblazer LS 4.2L MIL Lamp on, P0171 VIN: 1GNDT13S86
P0171: Fuel System Lean (Bank 1). ... know one can figure out. It is a 06 Trailblazer that keeps throwing a P0171 code. Whenever it feels like it. sometimes you can drive 20 miles and it sets and other times you can drive 400 miles before it sets. pulled it into the shop, i checked tsb. did fi...
January 04, 2010
2006 Chevrolet Trailblazer LS 4.2L MIL Lamp on, P0171 VIN: 1GNDT13S86
P0171: Fuel System Lean (Bank 1). ... know one can figure out. It is a 06 Trailblazer that keeps throwing a P0171 code. Whenever it feels like it. sometimes you can drive 20 miles and it sets and other times you can drive 400 miles before it sets. pulled it into the shop, i checked tsb. did fi...
January 06, 2010
2001 Toyota Highlander 3.0L Excessive Emissions, Misfire VIN: JTEHF21A91
P0171: Fuel System Too Lean (Bank 1). I've dealt with this code on Toyotas before, this engine utilizes air/fuel sensors, not o2 sensors, but what puzzles me is why the lean codes when the engine is obviously running rich? I mean it has black sooty plugs that were replaced a week ago and already h...
January 06, 2010
1998 Ford Explorer Limited 4.0L MIL Lamp on VIN: 1FMZU32E7W
P0171: Lean Bank 1. ... a Code P0171 and a P0174. The fuel pressure is good and the Air Flow Meter Tests Good. I smoked the intake system and found two vacuum leaks that were repaired. When I scaned the vehicle all the Fuel Trims Numbers (Both Short & Long) Show -100.6 % a...
January 08, 2010
2000 Ford Taurus SE 2-Valve 3.0L Poor Idle Quality, MIL Lamp on VIN: 1FAFP53U8Y
P0171: Bank 1 lean. Vehicle came in with CEL on, P0171, P0174. Customer said he replaced the PCV hose assembly because it was leaking. It was replaced and done correctly. Check for vac leaks, found none. Check MAF and baro readings w/ scan tool, everything looks good, cleaned MAF...
January 08, 2010
2000 Toyota Tundra 3.4L Cuts out, Stall, no power VIN: 5TBBT4811Y
P0171: Fuel System Too Lean (Bank 1). Truck was towed in for inoperative starter motor. Replaced starter motor with reman unit, now truck starts and will idle but as soon as we hit gas pedal it has no power and stalls. Scanner shows o2 sensors are going lean..Seems to be a fuel problem. LTFT +27%....
January 09, 2010
2000 Ford Taurus SE 2-Valve 3.0L Poor Idle Quality, MIL Lamp on VIN: 1FAFP53U8Y
P0171: Bank 1 lean. Vehicle came in with CEL on, P0171, P0174. Customer said he replaced the PCV hose assembly because it was leaking. It was replaced and done correctly. Check for vac leaks, found none. Check MAF and baro readings w/ scan tool, everything looks good, cleaned MAF...
January 11, 2010
2004 Jaguar XJ8 4.2L Misfire, MIL Lamp on VIN: SAJWA71C14
P0171: System Lean Bank 1. ... bank 1, P0301, P0303, P0305, check, for vacuum leak, made sure gaskets were good on dip stick, oil cap was tight, and Pcv gaskets good as well. found no vacuum lines loose or leaking. hooked up smoke machine to verify no ...
January 11, 2010
2004 Chevrolet Avalanche 1500 5.3L Excessive Emissions, Poor Idle Quality, Misfire, MIL Lamp on VIN: 3GNEK12T14
P0171: Fuel Trim System Lean (Bank 1). Truck is sort of intermittant but it always adds fuel to bank 1, and around 25% at idle though the pulse width looks the same as the other bank. Will sometimes run very well, next time VERY rough idle. Usually, #1 cyl will miss most, and some for #3, but now w...
January 13, 2010
2005 Chevrolet Silverado 1500 5.3L Misfire VIN: 1BGTYUII66
P0171: Fuel Trim System Lean (Bank 1). Fuel trim bank 1 is stuck at +25% WITH IGNITION ON and engine off. I have dis-connected battery and tried again, same results. STFT are at 0 on both banks. Plugs are black with soot on bank 1, beautiful on bank 2, cant find any intake leaks from the outside, ...
January 13, 2010
2000 Nissan Maxima GXE 3.0L MIL Lamp on VIN: JN1CA31A9Y
P0171: Fuel Trim Lean (Bank 1). code 171 setting mil light,no drivabilty complaints,smoke tested all intake system ,no leaks present,scoped injector patterns & all 3 02 sensors ok,injector pulse width slightly smaller on rear bank,fuel pressure & volume test all in spec,mass air flow...
January 14, 2010
1996 Ford E-150 Econoline 4.9L Poor Idle Quality, Stall, Misfire, MIL Lamp on VIN: 1FTEE14Y6T
P0171: lean bank one. ... day and had a code p0171 p0174 p0300 and p0420. we chose to go for the lean codes first in hopes they would also cure the others. found fuel trims short term maxing out nearly immediately after warm up at 33%. but when the engine is reved to 1500 rpm or mo...
January 15, 2010
2005 Ford Taurus SE 3.0L Poor Idle Quality, Surge, Melted intake VIN: 1FAFP56275
P0171: lean. This vehicle cam in with these codes a week ago. Found holes in the intake (melted) where the pcv hose goes into the upper intake. Also noted extremely hot pcv assembly hose. Checked for restricted exaust, checked ok. Replaced intake and pcv heater, and had a ...
January 15, 2010
1996 Ford E-150 Econoline 4.9L Poor Idle Quality, Stall, Misfire, MIL Lamp on VIN: 1FTEE14Y6T
P0171: lean bank one. ... day and had a code p0171 p0174 p0300 and p0420. we chose to go for the lean codes first in hopes they would also cure the others. found fuel trims short term maxing out nearly immediately after warm up at 33%. but when the engine is reved to 1500 rpm or mo...
January 18, 2010
2000 Chevrolet Cavalier Z24 2.4L Stall VIN: 1G1JF12T4Y
P0171: Fuel System Lean (Bank 1). The car runs perfectly until it reaches full operating temperature and has gone 10 to 15 km's. Stumbles once or twice then stalls as though the key has been turned off. If it sits for 15 minutes it will start up and run fine again. tested all parameters for ea...
January 19, 2010
2002 Toyota Corolla S 1.8L MIL Lamp on VIN: 1NXBR12E62
P0171: Fuel System Too Lean (Bank 1). ... code. i checked maf sensor it was only reading 1.3 g/s at idle i cant find any specs for idle but that seems low, what is normal for this engine?.maf was reading 80% calc engine load WOT at 55mph they say on identifix should be 80-85. replaced maf still se...
January 20, 2010
1999 Ford Taurus SE 3.0L Excessive Emissions, MIL Lamp on, Fuel Sytem Lean VIN: 1FAFP53SXX
P0171: Fuel System Lean Bank 1. Ok everyone this one's a killer. This car was brought by a lady who had it at another shop who could not solve this problem. Check engine light is on with bank one and two lean codes. Long term fuel trims at idle hang around 20 to 25. The second you raise the ...
January 21, 2010
2005 Land Rover LR3 SE 4.4L Excessive Emissions, Poor Idle Quality, Poor Fuel Economy, MIL Lamp on VIN: SALAA25435
P0171: lean code. ... with a mass air flow code originaly 3 months ago. fuel trims were slightly ellivated but ran good and no power issues. customer declined doing maf anyway getting good gas millage. Car back bad gas millage. Only code still maff code p0101, smoked intake had...
January 21, 2010
1999 Mercury Grand Marquis GS 4.6L MIL Lamp on VIN: 2MEFM74W5X
P0171: System too lean bank 1. Customer had no complaints other than CEL on. Ran codes and got the common 171-174 lean both banks. Did the MAF clean, check vacuum leaks, replace PCV,oem part. Checked for vacuum at crankcase with PCV plugged and no negative pressure. Cleared codes, test drov...
January 24, 2010
1996 Jeep Cherokee SE 4.0L Excessive Emissions, MIL Lamp on VIN: 1J4FJ28SXT
P0171: Fuel System Lean (Bank 1). Vehicle brought into shop with check engine light on , found o2 sensor no voltage. replaced o2 sensor everything worked fine for about 15 minutes. o2 sensor voltage with koeo reads 0.00 volts, if you watch scan data for about 5 minutes voltage will eventuall...
January 25, 2010
2000 Ford Explorer Eddie Bauer 5.0L MIL Lamp on VIN: 1FMZU84P1Y
P0171: fuel system too lean bank 1. ... explorer came in to me with the service engine soon light on which had been on for nearly a year. It is time for mass state inspection so it was time that he finally had to get it fixed. I scaned for codes and found p0171 and...
January 26, 2010
2002 Toyota Corolla S 1.8L MIL Lamp on VIN: 1NXBR12E62
P0171: Fuel System Too Lean (Bank 1). ... code. i checked maf sensor it was only reading 1.3 g/s at idle i cant find any specs for idle but that seems low, what is normal for this engine?.maf was reading 80% calc engine load WOT at 55mph they say on identifix should be 80-85. replaced maf still se...
January 26, 2010
2000 Ford Explorer Eddie Bauer 5.0L MIL Lamp on VIN: 1FMZU84P1Y
P0171: fuel system too lean bank 1. ... explorer came in to me with the service engine soon light on which had been on for nearly a year. It is time for mass state inspection so it was time that he finally had to get it fixed. I scaned for codes and found p0171 and...
January 27, 2010
2000 GMC 3500HD 7.4L Misfire VIN: 1GDKC34J5Y
P0171: testing and results. Engine idles fine and will rev fine if you give it just a little throttle. Try to give it a heavy throttle and the engine starts missing, if the throttle is held steady at any RPM the engine runs smooth with no miss but as soon as you try to give it some throt...
January 27, 2010
2004 Jaguar X-Type 3.0L MIL Lamp on VIN: SAJEA51C84
P0171: Lean Condition - Bank 1. ... codes P0171 & P0174. off idle fuel trims are normal. at idle in park lt fuel trims are both at 18%, idle in drive 19.5%. car idles beautifully and vacuum is 20.5". MAP reads 8.9" - 9.2" (we are just barely ...
January 28, 2010
2004 Jaguar X-Type 3.0L MIL Lamp on VIN: SAJEA51C84
P0171: Lean Condition - Bank 1. ... codes P0171 & P0174. off idle fuel trims are normal. at idle in park lt fuel trims are both at 18%, idle in drive 19.5%. car idles beautifully and vacuum is 20.5". MAP reads 8.9" - 9.2" (we are just barely ...
January 29, 2010