Trout13 Posted March 4, 2012 Report Share Posted March 4, 2012 The epc light is on all the time. Pal who is a mechanic checked the codes P0171/P1151 which bascially say running far too lean. He checked for any leaks and cleaned the throttle body and valve. He couldnt find any leaks and the problem is still there. I have searched previous threads on here but nobody seems to have got an answer.Has anybody ever got to the bottom of this problem?Getting desperateTrout13 Quote Link to comment Share on other sites More sharing options...
Trout13 Posted March 6, 2012 Author Report Share Posted March 6, 2012 I read on the web it may be the MAP sensor causing my problem, but it is not producing a fault code. Could it still be malfunctioning and not produce a fault code? Quote Link to comment Share on other sites More sharing options...
MikeyBopper Posted March 12, 2012 Report Share Posted March 12, 2012 Have the lambda sensors checked. Quote Link to comment Share on other sites More sharing options...
Trout13 Posted March 12, 2012 Author Report Share Posted March 12, 2012 Replaced the lamda sensor before the cat, didnt make any difference. The computer suggest they are both working fine. Quote Link to comment Share on other sites More sharing options...
Alan w Posted March 12, 2012 Report Share Posted March 12, 2012 Check fuel pressure and injectors,not common but either could cause a lean mixtureLeak in the intake system is a more likely cause so the best way to locate a leak is to Smoke test for leaks Make sure mixture adaptations are reset after fault is found Have you got the car long? It's possible a previous fault was found and rectified and adaptations were not reset which would cause these faults also Quote Link to comment Share on other sites More sharing options...
Trout13 Posted March 13, 2012 Author Report Share Posted March 13, 2012 My pal has cleared the fault a few times but im not sure he reset adaptations. It is not a VAG computer he uses but a generic/andriod one that does various makes. Will he be able to reset adaptations using this do you think? So when you clear the fault code it does not reset to a default setting?I have the car for about 1 1/2 years, fault started about 9 months ago. Quote Link to comment Share on other sites More sharing options...
Defcon5 Posted March 13, 2012 Report Share Posted March 13, 2012 16555/P0171/000369 - Fuel Trim; Bank 1: System Too Lean Possible CausesMass Air Flow Sensor (G70) defectiveIntake System Leak(s) Possible Solutions Check Mass Air Flow Sensor (G70)Check Fuel Pressure RegulationCheck Fuel PumpCheck InjectorsCheck Intake System for LeaksCheck Exhaust System for LeaksCheck Secondary Air System for LeaksCheck Vacuum Pipes for Leaks 17559/P1151/004433 - Long Term Fuel Trim Additive Air; Bank 1; Range 1: System too Lean Possible Symptoms Malfunction Indicator Lamp (MIL) active Possible Causes Intake System faulty/leakingFuel Pressure, Fuel Pressure Regulator and Fuel Pump faultyFuel Injectors faulty/leakingExhaust System faulty/leakingActivated-Charcoal Filter/System faulty/leakingSecondary Air Injection System faulty/leakingLambda/Oxygen Sensor(s) before Catalytic Converter faultyLambda/Oxygen Sensor(s) after Catalytic Converter faulty Possible Solutions Check Intake System for LeaksCheck Fuel Pressure, Fuel Pressure Regulator and Fuel PumpCheck Fuel InjectorsCheck Exhaust System for LeaksCheck Activated-Charcoal Filter/SystemCheck Secondary Air Injection SystemCheck Lambda/Oxygen Sensor(s) before Catalytic ConverterCheck Lambda/Oxygen Sensor(s) after Catalytic Converter Quote Link to comment Share on other sites More sharing options...
Defcon5 Posted June 30, 2012 Report Share Posted June 30, 2012 Did you get anywhere with this? Quote Link to comment Share on other sites More sharing options...
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