Hondata

- serial number of your K-Pro
- 3318

- KManager version (not 'the latest')
- 1.3.5.4

- what sort of vehicle you have
- '04 Civic Si

- what sort of ECU you are using
- PRB i believe. I bought it from somebody that had an RSX-S

- anything about the car which has been modified from stock which may affect the ECU (don't include what sort of rims you have nor stereo etc).
- k20a3
- JRSC 3.8" w/ 2.5" idler pulley and 62.2 gatorback
- Injen cai
- JRRH
- Comptech exhaust
- rc440 injectors
- 1 step colder spark plugs

- a specific description of the problem
- Symptoms about 2 months ago: Whenever I stepped on the gas pedal anywhere past feathering while the car was in neutral, the rpms would drop to about 500 revs, and shoot back up. When the revs are coming back down, the car almost stalls or it does stall.

When I was driving around and came to a stop sign, I stepped on the clutch and put it into neutral. It would drop to about 500rpm and catch itself, but it progressively got worse to the point where I would just take it out of gear and put it in neutral and it would stall when the rpms came down.

I replaced my belt. I've tried cleaning my IAC valve so it would spin freely. I tried increasing the idle valve duty cycle adjustment on kpro to the right 2 notches but it didn't seem to help much.

Symptoms now: The car doesn't seem to want to stay on, even when it's just idling.

One thing I did notice was that my SO2 value for the 2 datalogs is at 4.1V.

Thanks for looking,
Charlie

There are very odd things happening with the primary o2 sensor reading - it shows rich with the throttle released on overrun, but not all the time.

I think it is the o2 sensor, but there is a chance it is a bad injector or something else. Try replacing the o2 sensor first.