jeeper31

Yesterday I spent all day trying to get my O2 sensor out but couldn't. The only things I did were run the car, spray it with PB Blaster and unplug the O2 sensor. So basically you can say I did nothing mechanically to the car..... NOw the car is idling like crap. It seems to run fine and idle fine initially. After running it for a bit the idle fluctuates big time. The tach goes down to 0 and just before it stalls it shoots up to about 2000 and then back to where it should be. this happens repeatedly when standing still but the car drives without a problem. If I shut the car off and on again it goes back to runing fine. I drive away and when I stop it gets bad again. Did I inadvertently do something? The only thing I am thinking is the PB Blaster got into the O2 sensor and this is causing it to act this way. Any ideas?

Porsche-O-Phile

Even if it did, it would burn off almost immediately. I suggest letting it be until you can change the O2 sensor properly. Perhaps check other potential problems in the meantime - vaccum connections, TPS, etc.

pikey7

sounds like your idle valve is stuck wide open. Dunno how that happened though if you only messed with the O2 sensor!?

jeeper31

How do i check that?

Stan944

The trick in removing the O2 sensor is to do it on HOT exhaust. Still, I had to use 2 ft "extension" pipe.

patrick-87-944

I used Kroil (I have no intrest in the co.) on the exhaust bolts, o2, and manifold bolts and the stuff works. All of the bolts/nuts came apart after about 30-1hr of soaking in the stuff. I have seen it used in the industrial plants as part of their maint. stuff.

jeeper31

Seems to be getting worse. Car stalled twice. Sometimes the idle goes down to zero and then shoots up to about 2000. Embarrassing at a light.

Chris_924s

disconnect the O2 and see if it goes away. There should be a rubber quick disconnect plug near the cruise control unit.

jeeper31

If it goes away then what would that mean?

Techno Duck

...that your O2 sensor is causing your car to have idle problems.

The plug for the O2 sensor on the n/a 8v cars is at the rear of the engine, held in by a clip. Its directly behind the last intaker runner. Not sure if its the same for the S model.

Chris_924s

Thanks Jon.. exactly what I meant.

pikey7

Ahh, I see now. It's not a pulsating idle, its just either "on" or "off".? In that case, yes I agree, disconnect the sensor, and see if it goes away. If it does, bad sensor. Alternatively, it could be the throttle switch. There is a check to see if it's good/adjusted correctly on www.tech-session.com

jeeper31

Could I have done somehting the the O2 sensor? The car was running fine before I started to change it.

I just let the car idle for a bit. Seemed to almost die once when I first started it then seemed to level off. I am thinking it only happens after I drive it a bit.

pikey7

You "could" have done anything. They can be tempermental SOB's. Equally, it might have just had enough. Who knows with electronics!?

chimmay

the same thing happened to me today i was driving home from my dads and like i got to a light and the car was jsut idling like it wanted to die ...it would pulsate jsut like you said .....