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Discussion Starter · #1 ·
The title says it all.

The car has covered 130k and was running fine. It now has a massive decrease in MPG !! , it's usuing more fuel and back firing and also producing black soot/smoke. On idle is rough and bounces up and down below 1k rpm.

My Miltek Cat back system has loots of black soot around the tail pipes also.

Does anyone know what this could be ?

I have tried unplugging the maf and taking for a drive and seems the same to be honest.

Help me pls !!

James

P.S. It's a AGU running a Upsolute chip.
 

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Discussion Starter · #5 ·
would that be a cause of a lot of black smoke as well as popping and backfiring from the exhaust? Car feels like is pulling back sometimes
 

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would that be a cause of a lot of black smoke as well as popping and backfiring from the exhaust? Car feels like is pulling back sometimes
I'm not sure to be honest. I think a dirty throttle body is more likely because if the throttle is sticking open that would use more fuel. But I'm no expert on the oily bits of a car.
 

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seems as though its heavily overfuelling for which im sure the ECU would trip some fault codes, do a search on the VAG-COM section to see if there is anyone near you who could do a scan from this forum as I think this would be a good starting point.

You do however have a warranty with upsolute and they may be able to assist? as they remap may also cause this, I would also try calling them

HTH
 

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I would be interested to see what fault codes you get as i have noticed blackish marks around my exhaust and the car feels like someone has stolen the turbo out of it, very sluggish. Have also noticed that when i try to put my foot down it labours as if being starved of fuel, or air possibly??!!

Had about ten fault codes show ranging from fuel too rich to fuel too lean, had it serviced and the ECU reset to clear all the codes but according to Big Boyz Toyz they reckon on it being the MAF.

Has anyone else experienced this?

Cheers
 

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Discussion Starter · #9 ·
Hi guys,

I am paying Storm Developments a visit on Thursday to run vag com and try find out what is wrong.

When I mean black smoke I mean black smoke!!. gutted

Also, I used to get 27-35mpg on a motorway run, I now get........... 21-25mpg!!

I am filling up everyother day with the millage I do.

I will report back as soon as I know.

James
 

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Discussion Starter · #11 ·
I went to Storm Developments after work yesterday, they hooked up Vag-Com and ............

Pulled up fault codes relating to the MAF and the Lambda sensor. Both showed faults /failure

The guy showed me the fuel / mixture (I think) range the car should be in and lets just say no wonder I am drinking fuel.

Car is getting sorted next week asap and should be fine after.
 

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Excellent news there, VAG-COM really is useful for our cars, as the ECU will always pick the faults , hope it all gets sorted. Try German and Swedish for both the Bosch MAF and Lamdba, they are very competetive if not cheaper than the dealer.

HTH
 

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Discussion Starter · #14 ·
I got storm to replace the MAF and Lambda, they also said I had a leak form the inlet I think, which has now been repaired.

The car is driving fantastic again and now back to around 32-36mpg in stead of 20-25 prior to the problems being fixed.

Ta
 

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Discussion Starter · #16 ·
No Idea, but will try and find out for you. I was just pleased to find it pulling much better so didn't ask, I trusted their judgement as they really seem to know their stuff on the 1.8T's
 

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Would be helpful mate, rfsteel vag com'd mine and came up with a fault on the lambda but replaced that b4 guess it was a dodgy one so have to do that. My car sounds like it has the same problem you had also the air mass grams/per seconds stayed at 90 all the way through the rev range which aint good.
 
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