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golfpaul

Maf unplugged - what is the issue

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Hey.

 

Cars booked in to be looked at, but would like to gather as much info as i can on this.

 

Ive recently replaced the maf, the egr was deleted when remapped.

 

These are the codes with, and without the maf connected:

 

With MAF Connected
3FF1 air mass flow sensor
3F35 boost air hose monitoring in idle running
4530 charge air pressure control fault


With MAF Disconnected

4BC2 air flow meter signal
4BC7 Intake air temperature
4BA0 intake air temperature
4298 DDE Oxygen sensor - oxygen concentration implausibly low

 

Now, id probably expect all the disconnected codes as they seem to relate to the maf being unplugged.

 

What could the three codes relate to with the maf connected?

 

BTW - the car ran a little less gutsy than normal with the maf unplugged, the mpg did however increase, and the amount of exhaust smoke decreased!

 

Thanks.

 

 

 

 

Edited by golfpaul

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Yep I did go back a little while ago, they assured me the remap was correct.

 

Someone at work suggested an air leak after seeing those codes?

 

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I fucking hate diesels. Petrols are so much easier. 

 

My only suggestion would be to connect a scan tool and see what your fuel trims are doing.  Lean condition would suggest a vacuum leak.

 

If you don't see any real movement you know you might have a dodgy O2 sensor etc 

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2 hours ago, Deviant said:

I fucking hate diesels. Petrols are so much easier. 

 

My only suggestion would be to connect a scan tool and see what your fuel trims are doing.  Lean condition would suggest a vacuum leak.

 

If you don't see any real movement you know you might have a dodgy O2 sensor etc 

Thanks, good suggestion.

 

Does the MAF seem ok then?

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1 hour ago, golfpaul said:

Thanks, good suggestion.

 

Does the MAF seem ok then?

 

I don't honestly know. Just because it's new doesn't mean it's good. If air is getting in after it, changing it won't make any difference either. A quick and dirty test on petrols to look for a vacuum leak

would be to spray brake cleaner or similar around the intake and see if the engine responds. Don't think you can do that with diesels.But you could find a garage with a smoke detector

and get them to check or maybe even pay them to diagnose it and you do the work if it's something you can fix at home.  Have a look at those fuel trims first and see if they lead you any one direction or the other. 

Edited by Deviant

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Turns out the charge air line from the intercooler has a slit in it, so im on the look out for a replacement.

 

Is a diy temporary bodge possible on them?

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