afinuf1223
New Member
So I've been driving my 2004 civic si around just fine. I've hooked up a aftermarket stereo and that's it. The check engine light is on and I ran a code and it came back as o2 sensor. So I took it back to the dealer and they said they "replaced it". So I drove home and have been driving around for 3-4 days and it came back on. But it isn't running shitty like it was before they said they replaced it. Could it be because the ecu wasn't reset? Before the replace. It was bogging out and had rev limit at 4-5000 but now it doesn't. Does anyone know how to reset the ecu?
