danderson

I have a 1989 Turbo.

I will be installing an O2 sensor (for use with the air/fuel gauge supplied by Andrew Sweetnam) this weekend. A friend of mine designs and fabricates exhaust systems for motorsport companies and he has kindly said I can use his facilities at the weekend.

Ideally we would take the downpipe off the car so a new bung and sensor can be installed on the bench. Has anyone done this before?

Where is the easiest/best place to install the sensor if we are removing a section of exhaust to do so? Also would I need any other parts (gaskets etc.) if I was to do it in this way.

As my car is pre cat there is no O2 sensor as standard

Many thanks

Darren
'89 Turbo Pearl Black

special tool

DO NOT go through the hassle of installing a narrow band o2 guage. They tell you nothing. It is only a fast switch that aids an ecu system to know if it is rich or lean. Really - you would be a fool to do that.
You can get a wideband with a 6 channel datalogger (you do not neccesarily HAVE to use 6 channels) for $279. This is an instrument that will help you.
My wideband is installed immediately behind the front-most tube-tunnel brace.

Epic2112

I agree about not botering with the narrowband O2 sensor, it's utterly useless. The stock location for an O2 sensor on these cars is on the crossover pipe, not the downpipe. I think to get the downpipe out you have to remove the turbo charger as well, they come out together and you can remove them from each other out of the car. At least that's how I did mine, but my turbo was coming out anyway. The crossover pipe, while not being easy to remove, will be much easier than removing the downpipe. Maybe someone can post a picture of the location of the O2 sensor so you get a better idea.

special tool

Yes but DO NOT put a wideband between the turbo and the head.

Epic2112

Why not?

Tomas L

It seems that they don't tolerate heat as well as narrow band O2 sensors.
I haven't seen any real datasheet for a wbO2 sensor but the view expressed by most people is that it's to hot before the turbo.

special tool

A local friend of mine who cruises interstate 95 picking up junk has data to prove it - but I'll let him chime in

Too hot and way too much turbulence. He was reading rich and it was crazy lean.

Epic2112

hrmm, I guess I should move it then, huh? What a pain in the ***.

Ski

The amount of pressure and heat in the crossover pipe put the WBO2 sensors to an early exit. Even though the distance is not that far, there is enough "energy" used by the turbocharger to dissipate the heat and pressure, resulting in the test pipe being the preferred installation spot for WBO2 sensors.

That junk be a bumper cover that we read about the other day?

special tool

Dude - you already have it there??? ****. Dont tune like that - TOTALY bogus information. You have to move it.

Ski -

Epic2112

Yeah, it's in the stock spot, and it's been running fine for probably 5k miles. When I talked to the guys at Lindsey they said it would be fine there.

Epic2112

I should add that when I say it's been running fine, I mean so far the car feels right and hasn't blown up yet. Who knows what's really going on in there though.

jimbo1111

You guy's are correct as usual. I believe it's the pressure in the cross over that affects the reading. I just purchased another wideband for use on my new 951. The ideal spot for placement is the down pipe. But as you know this is a tough task to accomplish without the turbo removed. I had the turbo out 2 weeks ago but I totally forgot about the o2. I was to busy trying to figure out how to stuff that big *** turbo under the intake. ( out came the grinder) in went the turbo, forgot about the bug. So the next best spot would be the cat bypass pipe as close to the down pipe as possible. You have to get a little creative because there is very little room for a sensor there with a 3" exhaust . There are 2 spots that you can weld a bug with enough room for the sensor. I will decided for sure when I'm ready to start welding. PS who's bumper is still m.i.a?

David Floyd

How about this, right in front of the starter on the testpipe.

Ski

me too David. I might be a couple of inches higher, mine faces the oil pan in the little indention so that you can change sensors fairly easy, nice pic.