# MAF sensor P0100 code issue



## horhay (Aug 22, 2013)

This is my first time in this forum, so please forgive me if I'm not too technical. Still learning. 

I have a 2008 GTI 2.0t, everything stock, and I got a MAF sensor code p0100 issue. I would accelerate and the power would go out for a second and then come back. I took it to one mechanic and he said I needed to change the MAF sensor. After that, the code came back. I took it to another more trustworthy mechanic and he said I have a booster valve issue that he fixed. The code is still there, but i don't have any loss of power anymore. Now it just sounds different. It used to have a low purr sound and now it's more of a higher pitch purr. The mechanic said I should replace the sensor again and if that doesn't work, it's probably an electrical issue. Who knows how much that will cost. I don't want to spend almost 300$ again if it's an electrical issue, but I'd gladly pay it if it really fixed the problem.

My question is, after getting the new sensor, could the booster value problem have messed with the sensor enough to need to replace it a second time? 

I've also heard about cleaning the sensor with a special MAF cleaner. Could cleaning the sensor possibly fix the problem without buying a new sensor? Since the cleaner doesn't cost much, should I just try that first? Could it make the problem worse? 

I saw how easy it is to take the sensor out, and I know I can do it, but I just don't want to make a bigger problem. 

Any help would be greatly appreciated!


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## cameron2pt5 (Oct 19, 2006)

Sure, try some sensor safe cleaner. Let it air dry and don't use any compressed air. Also inspect the wiring harness and connector - I assume your mechanic checked this. Be sure to clear the code, if present. If it comes back, you need a new sensor most likely. RockAuto sells these for $120.


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## horhay (Aug 22, 2013)

Thank you!


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## ROH ECHT (Dec 9, 2010)

He said replace the sensor and that will *probably*? :facepalm:

No, your new sensor is OK. Cleaning it won't change anything...it's brand new. 
You still have the same code P0100? or is the CEL still on?
If you still have the p0100 code, you should have the maf sensor wiring checked.

BTW, he soaked you for replacing a boost controller that was fine...what proof did he have that suggested you needed a new boost controller? Which did he replace? The N249/DV?


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## horhay (Aug 22, 2013)

He's running diagnostics on the wiring today, but he doesn't have the cd with all the info for my specific model so he doesn't know what numbers the wiring should be at. He's looking for that now. (If anyone knows where I could find that info, I'm sure it would be helpful.)

I'll ask if it's the exact same P0100 code or if the CEL is on. I'm thinking it's the wiring.

About the boost controller, he said that there were two codes, the P0100 and another for the boost valve. I'll check the receipt and reply again with that code in a little and which one he replaced. 



If it's the wiring, how much should it cost to replace it? Would it be better to just take it to the dealership or maybe try a different mechanic? Or would it be possible to change it myself? I'm not an expert or anything, but I know how to follow directions well. I don't have a soldering iron though.



Thanks for all your help. I feel better spending money when I know more about what it's for.


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## horhay (Aug 22, 2013)

It was the wiring. Didn't cost much either. I'm just glad it's fixed. 

The turbo boost controller had a different code from the sensor and that's why it was fixed earlier. 

Overall, this was a good learning experience and now I'll do all my research here first before going to a mechanic. I appreciate all the help.


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## SickTRed08FSI (Apr 29, 2011)

What do you mean by wiring? Was a connection loose? If so, where?


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