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Marty, BMW Technician
Category: BMW
Satisfied Customers: 57124
Experience:  Bosch Certified Master Technician with over 35 years experience in the automotive industry.
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hi,bmw e39 530i 2002,diagnostics shows: 227-228 fuel trim

Customer Question

hi,bmw e39 530i 2002,diagnostics shows:
227-228 fuel trim bank 1-2 perrmisible range exceeded
202 fuel trim bank 1 control limit
Problems occurs when engine heats up a bit (10min)
complete data set:
fuel syst1-------OL FAULT
fuel syst2-------OL FAULT
144 CLAMP 15
139 CHIME 3
Submitted: 6 years ago.
Category: BMW
Expert:  Marty replied 6 years ago.
Hi, it looks like you either have intake leaks or the mass air flow sensor is bad. The intake system should be smoke tested for vacuum leaks. If a smoke tester is not available you can spray around the intake and the air hoses with carb spray to check for leaks. It's very common for the rubber hose from the air mass meter to the throttle body to split and set lean codes. Another possibility is a faulty crankcase vent valve. If the valve ruptures it will cause excessive crankcase vacuum and set these codes. A simple bit not always accurate test is to remove the oil cap with the engine running. If there is a lot of suction holding the cap on your vent valve is probably bad. The hoses from the vent valve can also leak and cause the lean mixture. A manometer is used to accurately check the vent valve. Low fuel pressure is also a possibility. A fuel pressure test should also be performed. Your misfire codes are likely due to the lean mixture and can be ignored for now. If you still get the misfires after the mixture codes are replaced you may need to replace the spark plugs or ignition coils. I'd also disregard the pedal fault until the mixture codes are repaired. Let me know if you have any questions.
Customer: replied 6 years ago.

can i drive like this or it could damage the engine

Expert:  Marty replied 6 years ago.
Over a long period of time it can be detrimental but you can continue to drive the car for now if the performance is ok.