Proper Placement of O2 Sensor

[PJG1173]

closed loop is disabled because of this issue. every time I enable closed loop things go down hill fast. WB says 14.7 and the NB shows blm of 145 and starts dumping fuel. I've replaced the stock sensor twice with the same results. from what I read this should not be affecting a heated O2 enough to cause this. I just pulled the truck off the lift after searching for evidence of an exhaust leak and nothing. just for grins I am readjusting the valves once the engine cools. I just don't understand.

[EagleMark]

Odd? Can you swap sides with the O2 sensors and see if one side has and issue?

[one92rs]

i have shorty headers where the 02 sensor is mounted in the collector of the header. every once in a while i would get an 02 sensor code. put in a heated 02 and that went away. maybe since they are ceramic coated. maybe just the way it is in there. seems to me it idled smoother ever since.

[FSJ Guy]

i have shorty headers where the 02 sensor is mounted in the collector of the header. every once in a while i would get an 02 sensor code. put in a heated 02 and that went away. maybe since they are ceramic coated. maybe just the way it is in there. seems to me it idled smoother ever since.

You probably solved one of two problems or both at the same time! Adding a heated sensor eliminated any problems of the sensor getting too cold. And if it was a 4 wire sensor, that added a dedicated ground which the old sensor may not have had. The ceramic coating may have prevented the sensor from grounding through the rest of the exhaust.

[EagleMark]

I wonder if that's PJG1173 issue? O2 ground? Wonder if you could just run a ground from O2 sensor to block?

[one92rs]

wow never thought about it like that. it is a 4 wire sensor. but 2 wires are tied togther which are ground, one signal, one power. but i do know it works great. since i will be going with headman ceramic long tubes in my engine swap it might be a good thing to have the heated.

[EagleMark]

IIRC four wire should have ground for power, ground to ECM or block, but not tied together... then power and sensor = 4.

[one92rs]

http://www.installationinstructions.com/103025.pdf

[EagleMark]

I was reading the LC1 heated wide band and it made such a big stink over grounds, but when I looked again today they do end up in same spot as you showed. So I stand corrected.

5. TheBLUE and WHITE wires should all be grounded to the same ground source
Optimally, these (and any other MTS device ground) will be soldered to the same lug, and
connected to a single point. When this isn’t possible, connect each one to a separate lug,
and attach in close proximity. Multiple lugs on the same bolt is not optimal, and can result in
unwanted signal “noise.” When possible, soldering is always better than crimping. Please
see chapter 2.3 for more information on Electrical Grounding Concerns.

[PJG1173]

hmm I might have to look into a 4wire setup

[FSJ Guy]

I bought a Bosch sensor P/N 15510. Less than $25 and I snipped off the attached connector and used a Weather Pack connector.

[JeepsAndGuns]

On the 4 wire sensor I installed, I tied the sensor and heating element wire together right after the connector and ran one wire to ground. Doesnt seem to have effected anything.