Drive By Wire

[MY02B4]

Hi all. Question for 6MT (or even 5AT) owners out there. I own a stock 6MT and when I come to a stop, I find the car likes to rev to almost 2000rpm then drops back down to 1000rpm. I find it quite annoying and I wonder if it's also the cause of the car being a bit jerky at times. Does anyone else have this problem?

Cheers.

[kiks]

When cold?
With aircon on?

[Dropz]

It's a Rev up feature on Subarus to help with emissions. It's gay.

[MY02B4]

Happens all the time irrespective of engine temp or aircon. At first I thought my foot was resting on the pedal but then realised it wasn't. Can this feature be tuned out?

[Jim]

Really?

Mine doesnt do that. Come to stop and steady 700/800 rpm every time.

[senator]

Could be a 02 or Air Fuel sensor on the way out

[Dropz]

Sounds like the rev up feature, but if your car doesn't have that then it could be knock sensor, or maf sensor. It's pretty rare for o2 sensors to stuff out normally but on gen 4 gt libs the first o2 sensor is a common fault, but it throws a code, ive never heard of it affecting the engine like this.

[MY02B4]

Yeah it's definitely strange. When the car is idling in neutral, the car shakes a bit at regular intervals but the revs do not move. When I'm driving it can feel a bit rough at times and I've always thought it was the road/tyres.

[subyroo]

My 2003 Man. XS Forester used to do a similar thing only it used to rev to about 1500 - 1700 rpm and then fall to 750 rpm, turned out it was the Neutral Switch and I always shift into 1st when stopping at the lights, just in case they turn green as you stop.

[Dropz]

If it's the neutral switch it often *not always* throws a cruise light as it affects the cruise control operation. Its pretty easily tested with the Subaru select monitor. As well as checking for the knock sensor etc. If you can't figure it out take it to a dealer, shouldn't charge more than 30mins labour to check it out on the select monitor and they should come back with a diagnosis.

[subyroo]

The idle problem was the only thing that showed in my 03 XS Forester, there were no other symptoms or lights on the dash lit up.

[Stu]

Sounds like a problem I dont want to try and fix

[dr20t]

Sounds like the ecu is staying in closed loop, thus the rev up (thinking it's in neutral) and the rough/ jerky driving.

Could be the 02 sensor, or even a bad neutral safety switch / wiring to the nss

On the gen4, the ecu stays in closed loop hen not in gear, and the only thing telling the ecu you're in gear on a manual transmission lib is the nss and I believe pin 82 on the ecu which relates to the and module

Do you find your abs isn't working when you have these jerky/rough engine behaviors? I know it's probably hard to say as you probably haven't tried locking it up when this happens but it could be a tell tale sign of your nss wiring circuit being out.

When it revs out like that next time, they revving it and see if you get a rev limit at 4000rpm which is the rev limit in closed loop I believe

[MY02B4]

That's a very interesting idea. Does that mean its always in a closed loop when in nuetral? If so,I can jsust rev it in neutral but i I will also try to rev it next time when it happens.

[db1]

Hi, did you find a cause to this?
My car has suddenly started to do this as well.

Thanks