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So I have a 2003 330ci with 175k miles and recently I’ve been having misfire with fuel cut off only at idle. I have new NGK laser platinum plugs, new oem Bosch coils, used oem injectors with low miles, new VDO fuel pump, new oe fuel filter. I am catless and also on e85 with flex fuel sensor. I have no idea why it’s still misfiring, I also have new intake cam sensor before this happened but have not touched the exhaust one. Rebuilt disa valve. Only thing I think about could be the MAF or maybe the o2 sensors not connected correctly or cam sensors? Any help would be appreciated.
 

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+1 on compression test....

what happens if you unplug the MAF and start the car (hot or cold)? If it runs better, you may have an intake leak..check all rubber boots, hoses, and caps on or near the intake..I have seen an intake leak appear as a single cyl misfire.
 

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2000 E46 323i, 3.0L and 2.0L Z3's
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What are your 4 fuel trims with a hot engine at idle and again when revving it to 3,000 rpm?

 

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As I mentioned in your linked thread.. I use the MAF test (only) as an indication that there might be a vacuum leak, not an indication of a bad MAF...It has worked well for me in this situation...

It often surprises people when I go look at a poorly maintained (e.g. orig intake boots) BMW with a rough running condition. I unplug the MAF, start it up, and it purrs like new.....I usually do this only after we have agreed on a price:D

Its a useful, quick test, requiring no tools...
 
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