96 4 wire o2 sensor confusion

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96 4 wire o2 sensor confusion

Post by Gavin583 »

Had to change front pipe on NA sw20 1996.
Previous owner or someone else had push connectors on the o2 sensor.
Of course I wasn't paying and in a rush didn't note the order.
On the loom side I have: black, orange, red/white stripe and yellow/brown
On sensor side: black, blue and 2 whites.

Anyone hazard a guess?
Getting car ready for mot and don't want to throw any warning lights on the dash.

Also when changing the front pipe I had a look at the back box and cat. Turns out the inside of the cat has been removed. Reading here and other forums seems the o2 sensor kicks in at a certain heat and with the cats inside cut out it might nit reach the correct temp. Doesn't sound accurate to me. Anyone on here have an opinion?

We all know this is the best forum anyways!
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Re: 96 4 wire o2 sensor confusion

Post by jimi »

As far as I can tell from the wiring diagrams, on the loom side the heater circuit is
red/white = from ecu
black/yellow = B+

The signal is
black = to ecu
brown = B- (earth)

The sensor I think is a bosch replacement
The 2 whites are the heater, polarity doesn't matter
Black is the signal to the ecu
Blue is earth (B-)
Black is not a colour ! .... Its the absence of colour
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