is there any way to tell what size an engine is? the car is a 2002 WRX and it is suposed to have a 2.0. the previous owner had a new engine put in when it died. I'm working out the various kinks. it is sluggish at low end, the turbo takes forever to kick in, and it occasionally gives a fule lean mix code. could it have ended up with a 2.5 from a later model and the ECU is not compensating well for the bigger engine? I think it just needs a lot more tweaking and the injectors cleaned ETC, but ...

It'll say on top of the block. I think on the driver's side, if I remember correctly. EJ20 is 2.0, EJ25 is 2.5.

thanks par. PITA to find under all the components, but it's the right engine. anyone seen anything on tuning the turbo?

i would hit up nasioc.com for tuning the stock turbo on the wrx.....alot of smart people on there and so much information.....