I have been trying to figure this one out for a while and have no clue what to make of it anymore. Maybe you have some ideas!
I have a stock '05 WRX wagon. The car idles great and runs like a champ once I hit 3,000+ RPMs, but in the low range it is frustrating. If I put the accelerator to the floor (sitting still), there is a significant delay before the RPMs rise and it is a very slow rise until the turbo kicks in. It also gets quite a bit worse as the weather gets hot.
I have cleaned the air filter and replaced (and gapped) the spark plugs, and will be putting in some injector cleaner tomorrow, but I can't seem to pinpoint any significant problems. Everything sounds fine and the car drives ok, but God forbid I take a corner and leave it in second gear...there is just no torque at low revs.
Maybe the 2.0L engine performs like this and I never realized it when I bought the car, but I am pretty sure that a Prius can outrun me right now (no offense Prius owners...). As a benchmark, if I rev my engine, it takes about 1-2 seconds to get to 6000 RPMs. 3/4 of that time is spent below 3,000.
Thanks in advance!