i need help cuz this check engine light wont go away and now my 06 wrx runs like ****.. it all happened after my friend "helped" me put on my downpipe. i drove the car around after the dp and the car was working fine for a day. then the check engine light came on so i read up how i needed a cel fix. i drove all the way to mpj in fremont to buy one and it still didn't fix the cel. i followed their instructions word for word, hooking up the cel fix then unplugging the battery to reset the ecu. the cel went away.. for away but came back. brought it back to mpj and it turns out the o2 sensor had no activity. it turns out the o2 sensor got messed up somehow but i dont know how. anyways, i found another o2 sensor that works off of a sti and plugged that in then resetted the ecu. i thought my problems would be fixed but the cel came back on. what can be wrong? i need help. do i need to keep driving the suby so the new o2 sensor can get use to the car? how many times do i have to reset the ecu before the cel will go away or was it not suppose to show up after the first initial resetting of the ecu.. can someone answer these questions? and what else can i do to fix this problem cuz if i dont, the car has a horrible throttle response time and is losing power.

btw.. mpj and the subaru dealer both had the same tests results and prior to the new o2 sensor and the tests results were that the old o2 sensor had no activity.

 

which 02 sensor did you change the one on the up pipe or down pipe?

 

It sounds like you wired the fix incorrectly. You didn't connect it to the front 02 by any chance, if you did that is your problem. In any case the best thing to do is get rid of the electrical fix and do the mechanical fix using spark plug anti-foul adapters. The info on this fix is well documented here and at NASIOC.
Also you should read up on the possible consequences of doing mods to the exhaust on the late-model WRX's without any engine management.