O2 sensor questions - Need quick help

[944tothefloor]

I am on a march to pass smog after tripling all the maximums. I have about 2 days!

I've searched this but couldn't find what I needed. I called a dealer and learned that my 1986 951 has a 3-wire o2 sensor because it's heated. Ok. So no one in my area has one in stock until tomorrow. Obviously I need to stick with a 3-wire part right? If so, I'll have to wait to tomorrow. How easy is it to do by oneself? I can't weld. Should I let a shop do this?

Also, I need a new cat. Is it common to do without the resonator? And does this make the exhaust bad and load?


Thanks!

[Techno Duck]

Get a universal 3-wire O2 sensor, you cut the old O2 sensor off and splice the new sensor on with the old connector. Bosch 15726.. should be in stock at any auto store. Its very easy to do.

Welding is not needed to replace, only requires a wrench (7/8" or 22mm) to get it loose. The sensor is located just before the turbo inlet on the drivers side; basically follow the exhaust pipe that wraps under the oil pan up on the drivers side, look straight up and you will see it. The only difficult part is routing the wire, the original O2 sensor wiring fits under a few heat shields and ends up inbetween the intake manifold and the firewall.

The 951 will sound fine without the resonator, n/a's are really the only ones that suffer that problem.

[John_AZ]

The new universal Bosch O2 sensors have a "Posilock" connection feature that eliminates any failure in the connection.



The current universal was Bosch 15725 and has been updated to the 15735

Actual install info:
Failed emissions with high NO

O2 sensor

If you buy a older style 3 wire Bosch without the "posilock" connection, DO NOT SOLDER the wires together. Crimp wires together in plastic covered electrical connectors.

John

[944tothefloor]

Thanks both of you. I'm going with a bosch 3-wire, after all. I think it's the 15735, but not sure right now.

[kfanazini]

I used this was not thrilled with the connectors.

Originally Posted by John_AZ

The new universal Bosch O2 sensors have a "Posilock" connection feature that eliminates any failure in the connection.



The current universal was Bosch 15725 and has been updated to the 15735

Actual install info:
Failed emissions with high NO

O2 sensor

If you buy a older style 3 wire Bosch without the "posilock" connection, DO NOT SOLDER the wires together. Crimp wires together in plastic covered electrical connectors.

John

[bell]

the connectors aren't too bad to deal with, use a quality pair of wire strippers (not those auto ones)....and.....don't solder them

[mytrplseven]

If you replace the cat, remember to get the one that's specifically for the California model or you'll bust the test again.