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Discussion Starter #1
Hello,

2008 X3 just began to run rough on idle stop and gives a jumpy start when accelerating from a stop or pass on highway. I do not have a CEL on.
I do have a Service Engine Soon light on.

Codes thrown are: 00303 & P00306 misfires on (coils #3 and #6),

P116E MAF sensor

P1771 Throttle Position Sensor

Question: Did the P116E and/or P1771 cause the misfires, or did the misfires cause the MAF and TPS to throw codes? Any thought would be appreciated!
 

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Clear all codes, see what comes back.

Clean the MAF (use only MAF cleaner).

Replace ALL coils and spark plugs. Plugs have a 60k mile service life; with that, coils should go 150k. Beyond 60k, coil life gets significantly shorted. As you didn't provide mileage, I'm going to assume that they haven't been done.
 

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Thanks DUKEDKT442. Mileage is 97,500. No CEL with two misfire codes? Possible?
Yes. Focus on symptoms, not which light is illuminated. You pulled codes for misfires, so that is where you should start.

Based on your mileage you need all new plugs 40k miles ago, which is why your coils are failing due to increased resistance.
 

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Discussion Starter #5
Thank you for the feedback. Hoping it will enemy the rough idle and jumpy acceleration. I***8217;ll update once this has been done. Thanks.
 

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Thank you for the feedback. Hoping it will enemy the rough idle and jumpy acceleration. I'll update once this has been done. Thanks.
Keep in mind you may have several issues to deal with, but the misfire is almost definitely coils/plugs. Lumpy idle may or may not be related.

Only use OE parts unless you want to do the job twice.
 
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