[RL14HER]

So my car is driving me crazy once again. I’m getting a misfire that seems to be completely random, I’ll feel one or two hiccups at times when I’m stopped at a set of lights or backing up into a parking space. Most of the time the car idles fine. It occurs much more often when the A/C is on so might have something to do with engine load. It’s an N43 auto with 51k, plugs and coils all changed and issue still there. The injectors were all replaced by BMW in 2017 due to a cold start misfire and the NOX sensor was changed shortly after that too. I’ve swapped out the MAF sensor for a second hand one I bought on eBay but no change. Any advice on what it could be would be much appreciated.

Thanks

[aaronblack]

Have you scanned for any codes? Any lights on dash etc?

[RL14HER]

No CEL or any other lights on dash. I haven’t got a OBD scanner so hoping to get some advice before paying for diagnostics

[aaronblack]

Very difficult without scanning. Perhaps somebody else could help, but my advise is if you have a bmw grab yourself a copy of ISTA it's free and buy a dkan cable. It's the best way to own a bmw outside warranty.

[Ice_maN_uk_pl]

Hallo!
I have simular problem but most of the time car is driving nice no problem. Sometimes got like a missfire for few seconds and come back to normal.
I can feel as hole car is shaking
No EML on dashboard
My codes are
0030E9 nitrogen-oxide cat converter, ageing
002EF7 map thermostat activation.
Any idea if the codes are relevant to this type of engine behaviour or should I focus to grab full service kit include ignition coils and plugs.
Thx for your time.

[N57]

I had this issue on my N43 1 series - replacing all coil packs fixed it. 3 Months down the line the car misfired and broke down. Turned out 2 fuel injectors seized open.

[aaronblack]

Originally Posted by Ice_maN_uk_pl

Hallo!
I have simular problem but most of the time car is driving nice no problem. Sometimes got like a missfire for few seconds and come back to normal.
I can feel as hole car is shaking
No EML on dashboard
My codes are
0030E9 nitrogen-oxide cat converter, ageing
002EF7 map thermostat activation.
Any idea if the codes are relevant to this type of engine behaviour or should I focus to grab full service kit include ignition coils and plugs.
Thx for your time.

30E9 shouldn't be as that's just NOx related. Is your car overheating? 2EF7 could be indicating that your thermostat needs replacing.

[Ice_maN_uk_pl]

Originally Posted by aaronblack

30E9 shouldn't be as that's just NOx related. Is your car overheating? 2EF7 could be indicating that your thermostat needs replacing.

No engine is not overheating. Plus I belive is integral to electric water pump. So needs to save some more money and get the water pump.

I check the injectors with ISTA procedures they seem OK no leak.

I will go with full service inc. coils and plugs and get an update of the topic.