My STi (98 V4) misfires a bit at low throttle,2-3k rpm. Problem disappears when I boot it.... ;-)

Probably not doing the cat much good though...

Any thoughts?

Serviced by Roger Clark Motorsport a couple of weeks ago - and they said the plugs were OK.

 

Does it do it everytime you run the car, or intermittently? Probably best to get the dealer to check for fault codes, 'cos it could be a number of things. Might be worth having a quick poke around under the bonnet and unplugging / plugging the wires to the MAF sensor etc, just in case of a loose / dirty connection. Good luck