power loss issue

[MidNiteImpreza]

ok i put a HKS down pipe in my 03 WRX, about a few days later the CEL came on ( wich was expected ), see the thing is , is that my car is supposed to be running faster with the down pipe and usually yeah it is, but some times... it seems just dog slow..., my buddy told me my car might be in limp mode, but i figured i would notice if it was in limp mode, then i was reading a issue on dirty MAP sensors and maybe that was the case but any how its driving me nuts, maybe im used to the car already ( ive had it for about a month ) i dunno, i have the studdering on accel that i see everybody else has, the idol is at 500 rpm wich is normal, i do oil changes mobil 1 5w 30 full synth every 2500 miles or so, so whats the problem argh!

[White 2.5rs]

try resetting the ecu
turn off the car
take off neg battery
push brake pedal
wait a few seconds

my friend had that in his 02 rex when we stuck a cobb cold air intake on it it was faster for a while then just got really slow, when it was in its maddslowness i think my rs was faster than his wrx that how much it had bogged

[MidNiteImpreza]

i see thanks dude, my buddy has a 2.5 RS i love those things, lots of torque, we had four people in the car and still had tons of torque, great car dude