MK4 Golf Running rich/hig emissions

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Sat 19 Nov 2005 13:55
MK4 Golf Running rich/hig emissions - mhspurs
Hi

I have had a nightmare with a 1999 VW Golf.

The car was running rich and failed MOT with high enissions.

It is vibrating on idle and gives of an extremely pungent fuel smell on idle.

My mechanic replaced the lambda probe, cat converter, cleaned out throttle body and replaced engine manifold to no avail (and £900 later).

Now he reckons its the ECU.

Could this be the problem?

Advice urgently required!!!!!!

Thanks
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Sat 19 Nov 2005 14:24
MK4 Golf Running rich/hig emissions - elekie&a/c doctor
Have the basics have been checked,spark plugs , air filter etc?I would think it very unlikely the engine ECU is at fault.High emissions on these can be caused by an out of range engine coolant temp sensor ,splits in air intake pipe .You say the lambda probe has been changed but is it an original spec part ?(usually Bosch)I have found that unless the correct sensor is fitted then the emissions will never be right.Also check engine oil level.
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Sat 19 Nov 2005 16:27
MK4 Golf Running rich/hig emissions - Screwloose
mhspurs

It might have helped a bit, to at least have given the engine type and size. The three-letter engine code would have been even better.

Before wasting your money on diagnosis by guesswork; why didn't your garage get the ECU scanned for fault-codes and live-data. It might have pointed them to the actual fault; which, if it's none of the good suggestions above, may well be the MAF sensor - if applicable - very easy to confirm from the live-data airflow/injector duration readings.
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