Does anybody know why my subaru is hesitating just as the boost comes in?

 

plugs? boost solenoid? air leak? overfuelling?

 

maf, fuel pump, driver error, need we go on? lol

best bet get it on a dyno and see what it says

 

In my case this was indicative of a failing MAF sensor. Going by your forum name you have a MY00, the MY99/00's are known to have less robust MAF's, so get it checked/replaced ASAP (70ish new) - could save a large bill later.

 

I've got an MY99 and this too was a problem on mine - until I replaced the MAF sensor... well worth the £70+ I paid.

 

Kev go with the MAF you are on a new block. Its prob the reason the old one went in the first place.

Go on, stretch them short arms down them long pockets and dig deep.

Craig

 

We can try mine on yours if you want.

If we reset the ECU with mine in place that will tell us if its the MAF.

You'll need to get a security torx bit off phil.

Craig