'87 Oxygen Sensor

[Hendog]

I replaced my O2 sensor last year with a wide band sensor; Bosch #15725. Lots of guys here reported they ran this sensor without issue.

I have a SW chip. I emailed Steve about the use of this sensor and he does not recommend it.

So now I'd like to find the Bosch # for the original. Does anyone know? Or do I have to suck it up and buy the Porsche OEM sensor?

[Steve W]

Hendog, when you asked me about installing a wideband sensor in place of a narrowband sensor, I had to tell you absolutely that would not work. However as you mention here that others have done it, I looked up the part number #15725 and that is a standard generic narrowband O2 sensor, NOT wideband, so that will work without problem.

[Hendog]

Thanks Steve. All this time I thought it was wideband. I feel much better now I'm trying to get this 3.2 to idle perfectly; it's good, just not perfect. Maybe I'm chasing shadows...

[Steve W]

a) use only NGK or Bosch coppers
b) check and adjust your base idle mixture
c) check and adjust your base idle speed.
d) make sure there are no intake air leaks
e) make sure your intake manifold gaskets are not leaking or sucked in
f) run some injector cleaner
g) make sure your idle position microswitch works
h) check and clean the inside of your distributor cap if necessary
i) check integrity of the vacuum lines/rubbers going to the fuel pressure damper on the right, fuel pressure regulator on left

[cgarr]

Just curious, how are these wired? 3 wire, what goes where? Are these heated and is there a relay?

[Hendog]

Originally Posted by cgarr

Just curious, how are these wired? 3 wire, what goes where? Are these heated and is there a relay?

Yes, 3wire. I believe they are Ground, +V for heater, and sensor. They go to a plug in the engine bay then back to the Motronic.

[Hendog]

Originally Posted by Steve W

a) use only NGK or Bosch coppers
b) check and adjust your base idle mixture
c) check and adjust your base idle speed.
d) make sure there are no intake air leaks
e) make sure your intake manifold gaskets are not leaking or sucked in
f) run some injector cleaner
g) make sure your idle position microswitch works
h) check and clean the inside of your distributor cap if necessary
i) check integrity of the vacuum lines/rubbers going to the fuel pressure damper on the right, fuel pressure regulator on left

a) NGK BPR6ES
b) and c) I'm playing with these
d) sprayed but found none; doesn't mean I didn't miss somehting
e) haven't taken those apart yet
f) rebuilt injectors
g) works
h) replaced cap and rotor and wires and plugs
i) yet to do...

I took the MAF off and checked it out. It's good. Now that's it's back on and I've played with the idle and MAF screws, it's improved. I probably have a slight vacuum leak somewhere. Some day I'll replace those intake gaskets...
Thanks for the check list.