Thread: Regrounding the O2 Sensor

i know home slice

Well thanks for the great info again mang!

I almost bought the 4 wire O2 sensor, but now I'll just sit back and wait for a confirmation...

I think the 4 wire sensor is the only way we can get a good 100% good ground (if thats possible).

I will attempt to find a better ground for my cat, and I will try grounding one of the header bolts and will see how that works

header bolt seems to be just what i planned on doing so....ill be happy to put in my 2 cents after i do so too

Guys check this info out

A thread about 3 and 4 wire Bosch O2 sensor...

I think I'm pretty set on just getting a 4 wire o2 sensor...

More info!

At This Link


I also read that not all 4 wire sensors were the same, so someone tried using one in a Civic but it tripped a CEL

Another thread, this one is going from 4 wire to 1 wire... here

Any news from Bosch about the differences between 3 wire and 4 wire?

During my testing, I found grounding to the header bolt actually gave the worse improvement. I grounded the header by attaching the strap under the center (U bracket) dogbone mount bolt and the other end under the bolts at the header/downpipe joint.



Great find! Especially the first link... My only concern is still the O2 output signal voltage range. But this does look promising.. This may require at trip to the junkyard for a O2 sensor & 4pin connector for testing. But I would still connect the ground wire at the same intake mani location as the regrounded MAS and the ECU.

No response from Bosch yet..

So I think that on the 3 wires O2 sensors it would be enough to find a way to ground the case, using copper strap, to a valve cover bolt and would be quite the same (if you dont wanna buy a 4 wires sensor). It just looks like the 4 wires one has a 12volt heater, which is good cuz it needs to be hot to produce a good signal to the ECU for a good air/fuel mixture... So it makes me think: how about regrounding it to the intake manifold?? What do u think guys??

What else would be good to ground/reground??? I already worked on my MAF and the idle and throttle response is a whole different story.

oopss, I didnt see your post since Im working at home and I'be been trying to write for about 2 hours...

Yea guys I think you have a great idea here, but i wouldn't go soldering anything onto the sensor. Solder melts around 350deg, and the 02 sensor is internally heated to around 400deg.

This thread brings up a great point. I remember when I installed my exhaust that i ripped the cat ground off and didn't think twice....just goes to show how much I have to learn....


Once again, thanks covert, for helping to keep all sr20's running tip top! And Scotty for the direct results/information.

Dudeman

Thanks Dudeman.. We are all learning something here. And if we only get a small idle or mpg improvement, thats still an improvement.

Soldering to the O2 outer exposed case has never been considered by me.. It gets too 600°F. Maybe wrapping the case with copper wire was considered though.. But after testing that, I found the only improvements were by grounding the threads only and grounding the exposed O2 case above the threads gave ZERO improvements..

Only improvements found was grounding the header & downpipe and grounding at the Cat. Also possible grounding the O2 sensor at the threads by wrapping a wire around the top of the 02 threads (if it can be sealed).