I just bought a MY96 5dr scoob, it was fitted with a HKS filter. I took this off to see if it makes it more drivable (for the missus). However, it drives fine really smooth through the gears, but is a little jerky on back off, and when i stopped the revs were dropping to about 350RPM and then back up to normal.

Please help - any ideas?

 

Also the check engine light is coming on - after reading some other posts, it sounds like ive disturbed a vac pipe somewhere - also where is the idle sensor on a MY96?

 

it may sound silly but have you just left it open going into the air flow meter? if so this will cause all of the problems you are describing. if not the throttle position switch is on top of the inlet manifold to the right it should be beige or grey in colour. but it sounds to me as though have got to much air going in through the afm which is sending a duff signal to the ecu & causing it to idle up & down.

 

Took it to Simspons in Swindon, they reset the ECU and now all ok - the techician said it was due to the iginition being turned on when the air flow meter was disconnected during the changeover, i didnt do this but i obviously caused an abnormality in the air flow meter circuit when i was fixing in the orginal filter assembley.

Car drives much smoother but less raw power, i hope to put in a quality high flow panel filter, can anyone recommend a good choice, i'm drawn to a K&N.

Any thoughts?