Hi,
I just installed the TC2 version2.5 into my 2.5RS (automatic)! I felt car had much more torque throughout the rev band, and also about 7hp gains (I guess). However, the rev is lower and unstable when it is idle. Is this normal? Any TC2 owners have the same problem?

Try to get Shiv's attention. He's the PEMS guru.

I just realized you posted twice in 3 minutes. Your problems are almost 100% from the TECII. Have you dialed it in yourself or are you using maps you got from someone else? It takes hours to get that thing completely dialed in, but you will see very noticeable gains from it. Make sure you start using 91 octane so you can take advantage of it.

Yes, I did emailed Alan about the unstable idle, and he said the ECU need some time to adapt the new setting! However, I got my first CEL today, and I think it was because of due to cold start. It was about -5 degrees celius outside and I parked my car over night when I started my car. My car started to tumble/shaking for about 6-8 minutes, and then calm down to normal idle. While it was tumble/shaking the CEL was blinking and then finally turned on! I tried to turn off and turn back on the car, but the light was still there. Is that I was having a knocking/detonating issue when the car was tumble/shaking? I just installed my TC2 v.2.5 for a few days, but it ran good before except the funny idle problem. At last, I changed from 92 octane gas to 94 two days ago, so I suspected that might be the cause of the proble too. Please help me!!!!!!!!!

My car spec:
Impreza'99 2.5RS (automatic)
KNN cone filter
TC2 v.2.5

My problem got fixed! It was because my spark plug wires had wear out and so caused misfire. My technician changed a new set for me and the car runs great now. The idle is back to normal and is very stable. I just want to thank you BAN SUVS for the help!

Excellent, we love to hear about each other getting cheap fixes to problems! Glad to help out, even though I had nothing to do with the solution, haha.

I don't know how but this post wound up in the wrong thread. I guess I wasn't paying attention. Things like this happen at 4:30 in the morning.

That's cool and all, I will be using a similar setup, but it has absolutely nothing to do with this thread.