The car has just started to play up. When slowing down and stopping at a junction the revs drop right down to almost 0 then hesitate and slowly climb to about 700rpm which is fine. I'm worried that it will stall. At one point the engine warning light came on too. On a couple of occasions it's reved up and down between 0-700.

It has a decat exhaust+scoobysport BB and K&N panel filter. Is this anything to do with it???????????

 

Probably the 02 sensor in the downpipe.

Mine did this, replaced the bit under warranty, ecu reset and its now fine. Other thing could be an air leak or MAF sensor.

MB

 

I concur - a dodgy idle is usually caused by either a dodgy Lambda/O2 Sensor, MAF (air flow meter) or Dump Valve.....

Matt

 

my money is on an atmo dumpvalve.....

 

Had exactly the same problem in MY99 just a couple of months ago and I know just how annoying it is!

Dealer initially told me there was no problem with the car but the problem only showed up when the engine was warm and when I was approaching roundabouts and coming to a standstill! Rev counter was bouncing around all over the place!

Replacement of the Air Flow Meter under warranty has definately sorted the problem since then.

I do beleive it would have cost somewhere in the region of £227 + VAT from the dealer.

HTH

 

I bet vent to atmosphere dump valve too.

 

If it's a MY99/00 car then my money is on the MAF sensor.

Happened to my heavily modified car, and to a friends standard car. They are just fragile! There seems to be no pattern.

 

Never had any probs with my V 2 A DV, but had the MAF replaced after experiencing the probs you mention.

 

Just try to unhook the maf sensor when it is stalling!
If it goes away its the maf.

Skassa