Recently I received a code for P0150 (b2s1) and I bought a universal 4 wire (2 white, 1 black, 1 grey) bosch o2 sensor. When I started to replace it, I noticed that the old sensor is a 3 wire (2 white & 1 black).

Now what should I do with the grey wire on the new sensor? Will it function the same if the grey is left disconnected?

 

Return it, get an OE fit. Done.

 

Does your universal say what wire color is for what function?

4 wire O2 sensors generally just have an extra ground, whereas the 3 wires don't. For OE sensors, anyway.

 

hmm, i jsut bought a bosch universal o2 sensor yesderday and it had 3 wires. It tells you how to match up the wires on that paper they give u.

 

i bought 3 new bosch uni sensors. two 3 wire($40) and one 4 wire. I wish i would have paid the $9 extra to get OE fit($50)

 

Yep, the grey was a ground. Grounded that wire and now all is good according to my scanner