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Discussion Starter #1
hello everyone!
bought 2 x5s this month
1 is a 2006 v8 with no issues !!
the other is a clean 2003 3.0 with a p1343 code
(misfire cylinder 1 with fuel cut off) and very rough running until i unplug the maf then i get full power restored and drives like a dream with a slight rough idle. also with the maf unplugged the p1343 is gone and replaced with the P0102 (maf circuit low)...
so far I've only changed plugs swapped coils(misfire stays with cyl 1)


has anyone ever experienced this or better yet solved a similar situation?
thanks.
 

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I've watched several how to videos on diagnosing misfires and am not a pro. I recall troubleshooting guides saying if coil and sparkplug is good via testing, try to see what the compression is (Google) to further diagnose. Could be a bent rod, or piston problem.
 

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I would replace the MAF as it can cause the car to have a misfire when it goes bad. To my understanding the code for the misfire went away when you unplugged it then that means that the MAF is causing the problem. Try cleaning the sensor with MAF cleaner you could get it at your local auto parts store.


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What's a MAF?? I'm having 4 misfire codes on my 2005 X5 3.0 also the secondary mass airflow sensor code. I've replaced that as well. I know there's a main mass airflow sensor and then the secondary. What were you talking about?

Thank you, Deborah
 

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I’m talking about the mass air flow sensor for the air intake. The secondary wouldn’t really cause a misfire. But the main one can and I would try disconnecting it and see if the misfire goes away. Also look for air intake leaks


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Oh Mass Airflow Sensor MAF da

What's a MAF?? I'm having 4 misfire codes on my 2005 X5 3.0 also the secondary mass airflow sensor code. I've replaced that as well. I know there's a main mass airflow sensor and then the secondary. What were you talking about?

Thank you, Deborah
Oh Mass Airflow Sensor MAF. I should have known LOL... Well, the airflow system is having codes and the miss fires are 1-4, maybe the coils on the spark plugs?? Please help if you've had this issue. :(

Thank you, Deborah
 

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If it runs good with the mass air flow sensor disconnected then I would assume the mass air flow sensor is bad.


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If it's working how will the car run? Should I also do the same with the secondary mass airflow sensor? Thank you for your quick reply :0)

Deborah
 

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If you don’t have any misfires with it disconnected then it means that the MAF is possibly bad. You can try the secondary too to see how it rubs


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Do I have to reset the code reader and start a new test? While it's unplugged? It would most likely be a different code, but the original would be gone, right?
 

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A new code will come up for the MAF being disconnected it would say something that the values of the MAD aren’t able to read or something. If it fixes the misfire codes then the codes will not come back.


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