Well my service engine soon light came on today and won't go off. The car seems to be driving normally without any hiccups. I'm thinking its the UR 3' inch highflow cat I installed about 500 miles ago. I've read other posts regarding the light coming on because of their cats but I'm not sure thats the problem.

My current mods:
Cusco Induction Arm
B&B turbo back
UR high flow cat (3 inch)
RMR filter
Forge DV
Lineage grounding kit
Walbro 255
HKS TT
Greddy profec spec b
Apexi super AFC (set on 0 and not doing anything but looking good)
Dynoflash

I dynoed at 302.5 before cat and about 310 after. I had no problems before the cat, but 500 miles later???? If it is the cat I'll be freaking pissed cuz that one of the reasons I went with it, to avoid the cel. After class tonight I'm going home and reseting my ECU (unhook battery and step on brake, then rehook). The light will go out but for how long.

If it does come back on I'm going to the dealer to see WTF is going on. If it is the cat UR got some explaining to do. I wonder if since the CEL is coming on will I pass emissions?

 

Naa I would throw random rear cat defficiencycodes all the time with my UR high flow cat. I called Daryyl and he sent me a test pipe on the house. Never thrown one since with their test pipe design!

 

you don't have to unhook the battery to reset the ecu.
pull the #8 fuse in the underhood fuse box for 10-15 seconds, (or pull it and turn on the lights for a second), then put it back in..RESET!
By the way, I'm working with Pony Express Performance on a CEL eliminator.
I've tried their WRX model but it eventially threw a CEL (P0139 code, which is a slow circuit code).
It seems the STI guys have the same problem, the ecu works faster and needs a faster signal response from the CEL eliminator.
They have fixed the STI CEL and Dan from PEP sent me one to try out on the Evo. I'll put it in tomorrow, will post results in a few days to make sure the CEL doesn't come on.
www.ponyexpressperformance.com