1988 3.2 Unplug the O2 sensor?

[Snitzler]

Need some input -> Problem with 3.2 transplant going lean and misfiring after two min

1988 3.2, I have been following the above thread and I found a comment about disconnecting the O2 sensor because it makes the car run better. Is this true?

[Roswell]

NO! Especially if you have chipped the engine.

[Lyle O]

Everyone has their own opinion (especially if it is colored by experience). In the tuning and modifications I have done, getting input from people like Steve Wong, Todd Knighton, etc., the consensus from them was that, as long as the system (Motronic) is in good order, the narrow-band O2 sensor is good, AFR values are good, and there are no leaks, etc., it makes sense to leave it plugged in. This is how I am running now, and it is fine.

Of course, now I will probably go out to the garage, unplug it, and see if I notice a difference...
YMMV.

[Hotshot]

After dealing with a high idle, SW chip, and a cat bypass.. I decided to unplug mine and its been great. Had it hooked up to the old shop C02 machine and with or with out was negligible. Smogs not an issue here but was just in spec. Ran smoother without. Decided to unplug it... RUNS AMAZING. So I'm leaving it out. ill pay for the .3L of fuel... 2500km like this and its great..

3.2 86 Targa

[proporsche]

always unplug...it... unless you need to go for an inspection where it is required...it is there for emission purposes .All 911 in Europe and the rest of the world do not use the oxy sensor at all...when i worked in CA for 25 years on 911 always unplug unless you went for smog test......

Ivan

[GH85Carrera]

My 1985 runs just great, with it plugged in. It starts stone cold or hot and idles just like it should. No hesitation and pulls strong to redline. I can't imagine how it could do better with the sensor unplugged. I suspect the garage would stink more with the rich mixture.

The good news, it is real easy to plug it back in so trying it does not hurt much.

[mysocal911]

Originally Posted by proporsche

always unplug...it... unless you need to go for an inspection where it is required...it is there for emission purposes .All 911 in Europe and the rest of the world do not use the oxy sensor at all...when i worked in CA for 25 years on 911 always unplug unless you went for smog test......

Ivan

Good way to shorten the life of the CAT! The early 911 3.2 Euro didn't use a CAT.
Ask any qualified 911 tech in CA, they'll say leave the O2 sensor connected.

[proporsche]

here you go ....most of the disconnected oxy sensor-you should know by now- is on 911 where the cat has been removed and replaced with straight pipe...dude;-))))))Most of the Euro do not have Cat, it was an option to get better insurance price..i had a feeling you are picking around the corner Loren;-)))))
...sure i go look for qualified 911 tech in California --you make me laugh----maybe Swiss Motors remember them???



Ivan
btw i have an early model of Euro 911 and it came with CAT...

[BER]

This is like a discussion of which is the best oil for our 911’s....no clear cut consensus, but lots of opinions. 🙄

I have a euro pre-muffler (I.e. no cat) and a SW chip in my 84 911. I have run with the O2 sensor connected and disconnected. I really could not tell any difference. My suggestion is do which ever makes you happy.

BTW-JG Driven GP-1 20w50. 😉

[NY65912]

I have a euro pre-muffler and a Steve Wong chip in my 85 911. I run with the O2 sensor connected.

No issues, especially after refurbishing the entire intake system a few years ago including sending out the AFM and having the injectors rebuilt. No raw fuel order any longer.

[Nick Triesch]

I believe the owner Of this site says it is important to leave it plugged in. Porsche says to leave it plugged in. My high end Porsche shop says leave it plugged in. My 85 Carrera runs perfect, I’ll leave it plugged in.

[proporsche]

as i have mentioned it is for emission purpose..only USA models(mainly CA) have it in almost all 911. Europe and the rest of the world nobody really uses the oxy sensor and cats;-)

Ivan

[Marc Bixen]

Originally Posted by BER

This is like a discussion of which is the best oil for our 911’s....no clear cut consensus, but lots of opinions. 🙄

Like he says, lots of opinions.
Red Line Service says..................LEAVE IT PLUGGED IN!

[proporsche]

Marc..that is for USA models ....others do not even have it in the system;-) correct;-))

Ivan

[Marc Bixen]

Ivan, play games with Dave, not me. If the car has the system, if Porsche and Bosch and their thousands of engineers, spending millions on component development, say it is right for the car, who are we to question it? You're talking like these guys who develop performance chips, yea they may get you more power, raise the red line to an unacceptable level, or advance the timing to an unsafe level, but in the end, they can't develop a better all around chip, that brings into account all the possibilities . It may diminish fuel economy, engine and or component life etc. If you want the lowest maintenance costs, the most diverse drivability, stick with stock.
That's all I've got on the subject. NEXT THREAD!

[70SWT]

A 3.2 I had would run way too rich without the O2 sensor installed.

[proporsche]

Marc..no games unintended ,dude..just wanted to mention that the market made the catalyst for US mainly, for the rest of the world they do not use catalytic converter and oxygen sensor it their models..

Ivan

peace;-)

[Big Dav]

Originally Posted by proporsche

for the rest of the world they do not use catalytic converter and oxygen sensor it their models..

In Australia (Porsche Code C23) we had catalytic convertors on 911's from 1986 onwards. I think the same is true for cars delivered new to Japan and Switzerland.

But I agree that a well tuned 3.2 with idle mixture set correctly will show little difference with the O2 sensor connected or not. I know with my car I have monitored AFR with and without the O2 sensor and it only has an effect at gentle highway cruising and some minor effects at idle.

With my Australian delivered car I have a sports cat fitted and the O2 sensor connected and it idles and runs beautifully.

[proporsche]

thanx good to know;-)

Ivan

[Porsche 935]

I deleleted my O2. Set mixtures and idle to spec and runs perfect without worrying it might fail in the future. On 84 Carrera, one less thing to worry about.