does anyone know if it is normal for the enginge to dip power when idling?

i have an 03 blobeye WRX and noticed that when the car idles the engine power dips now and again.

 

Could be the MAF sensor. Got any mods? Such as new air filter.

 

Have you got the air-con on

 

I have the air-con on in my MY03 STI and never noticed the rev counter fluctuate at stand-still.

 

Mine's always done this from brand new. It seems to vary according to the fuel used. Hardly get it at all with Esso Super - its pretty bad with Optimax and Ultimate (what I use cos its close).

To be fair, the car's never actually stalled...

 

With the A/C on mine dips as the compressor kicks in and out

Other than that, yes it could be a MAF issue. Have you noticed a flat spot in the power delivery at around 4k revs If so, get it to a dealer or specialist with diagnostic equipment for a quick check-over. If the MAF has failed it could run lean and that is piston-meltingly bad for Scoobs

 

air con wasnt om

fitted new backbox the other day. could it be that

 

I have this same problem on a 93 WRX. The car was idling fine until I changed the air filter and plugs yesterday and now about every 12-20 seconds or so the car seems to 'shudder' although the rev counter doesnt seem to drop.This happens wether the car is cold or warmed up. I did an ECU reset after changing the plugs and filter and didnt get any error codes.
Havn't noticed any problems when driving and it doesnt seem to be losing power anywhere through the rev range, just seems to be doing it when idling.
I changed the existing panel filter (jap aftermarket panel that was on the car when I bought it)for an STI panel, could this be causing the problem? or could it be the coil packs/plugs?
I did read in another thread that 'they all do this' but never noticed it before I changed the plugs and filter.