20VT fault code - fuel mixture too rich ??

[Wingman]

Got a recurring fault code (17545) on a 2001 20VT Golf GTI - comment from diagnostic check says "bank 1 mixture adaption (add) system too rich".

Other sysmptoms (not sure if related to above fault) are that periodically, particularly in 2nd gear, car hesitates when you apply throttle at lowish revs, only momentarily, then power delivery is as normal - although this is not happening all the time.  Also, the engine management warning light has come on, will stay on for a while, then go off for a while and come back on ??

Local VW independent has had the car in and commented that problem is most likely due to some sort of leak - but can't trace anything.

Any suggestions, anyone come across this before or have any tips on who to speak to who knows everything there is to know about the 20VT lump ?

Cheers.

[GazB]

Check all of your turbo pipes for any leaks or loose fittings, as for the small delay in second then this may be down to Lag .

When was the last time that you changed the plugs?  May be worth a shot too if its been a while.

[Dizzie]

my money is on a dodgy MAF. worst invention ever!

[GazB]

Could be Maf too, and your right, they are a pain in the arse

[Wingman]

Done some research and VW independent guy says that its a fuel "additive" issue (the fault code does refer to additive) and therefore only a prob at idle - apparently there are two categories of faults - additive or multi - with multi being a fuel mixture problem across the rev range at various throttle positions.  He says that it's therefore unikely to be either MAF or the bank 1 lambda probe (ie: the one before the catalyst).  But VW dealer (although they have not had the car yet) is pointing to either MAF or Lambda probe.

Any thoughts ??

Cheers.