Intermittent over idle after warm up.
 

Hi guys.
Bit stuck on this one.
​​Car starts and warms up fine but on occasion it starts to over idle. 1500 to 2000.
been into the garage twice and not done it. Second time it did flash up the post turbo 02 so fitted a new one today.
seemed better but still the same after 10 mins.
​​Got home and reset the ecu again and ok again.
Any suggestions?

Wat car?

Sorry, MY00 UK Impreza turbo 2000.

Clean IACV then if no luck replace MAF.

On my99/00 the IACV is a stepper motor which is handy cleaned, 2 screws releases it just be careful with the O-rings

Just incase you go googling and get look at gaskets n all for early years which have an actual IACV as such

Thanks ill do that 2day. Is there anyway to test it when out?

after cleaning, you can reset ecu, my opinion

you can check stepper motor clearance, mine was little loose, and engine stopped 3-4 times before changing new one