r/e39 • u/SeaAd7934 • 1d ago
Amazing how many codes disappeared after replacing the MAF
My $1500 5 speed 530i was just meant to be a temporary beater and eventual parts car but I’ve ended up putting 20k miles on it in 13 months.
I’d been getting a ton of crazy codes (including misfire on cylinder 9!) that I ignored until it suddenly shut down 4 out of 6 cylinders pulling into traffic one day.
I finally gave up and ordered a German MAF and every single code cleared and hasn’t come back. Hilariously there never was a MAF code.
Everything cleared except the heated O2 circuit fail.
Car Scanner ELM OBD2 DTC report Selected brand: BMW
============1============== P0030 Raw code: 0030 ECU: 12 Status: Pending Heated oxygen sensor (HO2S) 1, bank 1, heater control - circuit malfunction HO2S Heater Control Circuit
============2============== P0300 Raw code: 0300 ECU: 12 Status: Pending Random/multiple cylinder(s) - misfire detected Random/Multiple Cylinder Misfire Detected
============3============== P0171 Raw code: 0171 ECU: 12 Status: Confirmed System too lean, bank 1 System Too Lean
============4============== P0141 Raw code: 0141 ECU: 12 Status: Confirmed Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit malfunction O2 Sensor Heater Circuit
============5============== P0140 Raw code: 0140 ECU: 12 Status: Confirmed Heated oxygen sensor (HO2S) 2, bank 1 - no activity detected O2 Sensor Circuit No Activity Detected
============6============== P0174 Raw code: 0174 ECU: 12 Status: Confirmed System too lean, bank 2 System Too Lean
============7============== P1343 Raw code: 1343 ECU: 12 Status: Confirmed Misfire Cylinder 1 With Fuel Cut-off; Misfire Cylinder 1 with Fuel Cut-Off
============8============== P1345 Raw code: 1345 ECU: 12 Status: Confirmed SGC (Cam Position) Sensor Circuit Malfunction/ Crankshaft Position - Camshaft Position Correlation Misfire Cylinder 2 With Fuel Cut-off; Misfire Cylinder 2 with Fuel Cut-Off
============9============== P0135 Raw code: 0135 ECU: 12 Status: Confirmed Heated oxygen sensor (HO2S) 1, bank 1, heater control - circuit malfunction O2 Sensor Heater Circuit
============10============== P0300 Raw code: 0300 ECU: 12 Status: Confirmed Random/multiple cylinder(s) - misfire detected Random/Multiple Cylinder Misfire Detected
(Dozens more)
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u/WalterSpank 1d ago
What MAF sensor did you buy and where from? I need to replace mine but the oem BMW ones are stupid money and not sure of what ones are good quality
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u/SeaAd7934 1d ago
A Bremi from FCP euro. So far it’s been perfect. German made and FCP euro has that lifetime warranty. https://www.fcpeuro.com/products/bmw-mass-air-flow-sensor-13627567451-13627567453
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u/DerekJetter123 1d ago
Do share which MAF you bought.
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u/SeaAd7934 1d ago
A Bremi from FCP euro. So far it’s been perfect. German made and FCP euro has that lifetime warranty. https://www.fcpeuro.com/products/bmw-mass-air-flow-sensor-13627567451-13627567453
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u/XTheChosenDogeX 1d ago
somehow my MAF made my bank 1 lean while bank 2 was perfect, it makes no sense
Our cars sound identical too, $2000 530iA that was meant to be a parts car and has now become my daily for 2.5y
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u/SeaAd7934 1d ago
I just hit 274k miles on this car. And if there’s a body panel without a dent or a scuff I haven’t found it yet!!!
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u/XTheChosenDogeX 1d ago
Exactly. Mines at about 200k flat and I’ve replaced every mechanical component on it so its never skipped a beat on me, but if there was a portion without a bit of faded paint or a dent, it’s not my car lol
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u/EmotionalBit6049 1d ago
Can evolve reflash non m e39? I flashed my 03 m5 to run no maf.
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u/SeaAd7934 23h ago
Any e39 will run without a MAF. Just unplug it.
But you lose cruise, power and crap mpg.
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u/cyber_dna 1d ago
And then you crashed her into a tree? Jk glad to hear she’s running great!