3 Wire O2?

[Movin]

Sketch has brought up very good questions and newer tech did not happen just to cost us more, ( that is probably debatable ) I think he is right, especially for short trips like I do going to work every day. The mileage and clean burn can be improved. Trips into the desert or mountains not so much.


I have a couple almost brand new four wire sensors.

http://www.miparts.com/oem/000%20540%2081%2017

The connector would be cut back off and the wires butt connected as needed.

Sketch, this is your post, if you want one of these almost new sensors PM me and I will mail it to you. I have also have some well used but working 4 wire and 3 wire sensors if you want one of them instead.

The almost new are out of a s1 location E series v8 mercedes, 2001 year.

[sketchman]

I appreciate the offer, but I just got one in the mail. Will be doing some testing ASAP, after I establish a baseline from the change to 14" wheels I have now.

[sketchman]

It's in. Power on run is done through the 30A fused connection for the seat-belt junk. I don't use the power function of them anyway. Ground is straight to the battery neg.
If you want to ensure maximum street cred you can also grab a factory GM connector to butt in to the stock wiring and the power/ground sources. This also makes future replacements easy as stock.


Still no results yet. I'll know soon, though.

[sketchman]

^Realized the power belts are always hot. DON'T use that one. Swapped to the lighter fuse. Can't believe I did that.

One other thought I had. You could probably make a 3 wire just as accurate as a 4 wire by grounding the sensor body instead of relying on the exhaust as a ground. So you could still use the cheaper sensor that way.

[sketchman]

MPG dropped to 43 after the wheel/tire/brake swap and similar driving. Not sure what a normal drop is for the setup I have over a stock setup with the stock O2, but I'm OK with it. I can swap back to the 1 wire O2 and see the difference after I run through another tank to be a touch more accurate.

[sketchman]

Ran another tank through. Seems to be staying around 42-43. I left the stock 1 wire connector in place, so I'll put a stock sensor back in and see what the difference is, if any. It should be minute with my usual driving, but if it shows a difference those driving mostly in the city should see a decent benefit from it.