With my downpipe and front bung location my 02 sensor harness is a tad bit to short. Is it okay to extend the harness? What would you do and use

 

Bump

 

Got no response to if i should extend the 02 sensor harness or not. Guess i should weld another bung in instead

 

Its always better to cut into the exhaust than to cut into wiring. It is all personal preference though. The wires are exposed to a lot of water and salt this time of year which would only promote corrosion. If properly done you will not have a problem.

 

The car is not driven year round. Its a race car. I just need to know if i can cut and lengthen the 02 sensor wite harness up to the plug. Or should i lengthen the car harness itself? What is the proper way to lengthen them

 

If it is the rear o2 then you can just disable it and remove it from the car. It is one of your options instead of lengthening the wires.

 

No its the front. And the bung is too far down on the downpipe

 

Correct way of extending a harness is different between anyone. I do not know the actual standards automotive engineers use when designing a harness and such but I know how thorough you can be if desired. If you are starting with a harness from scratch such as a wire tuck etc, I would purchase the pins and wires and run it from the ECU to the sensor without any splices into the wire. Clearly that is not an option for everyone so if you want a quick and easy setup that still very durable try a non-insulated butt connector and some adhesive lined heat shrink. Lengthen it on the harness side NOT the o2 sensor side. This way if the sensor ever craps out you don't have to keep lengthening them.

 

That sounds about right. So instead of cutting and soldering the 02 sensor harness actually cut and solder the car harness itself longer. I wont have any issues with getting a false reading due to resistance change?

 

if you use the same gauge wire, you will not have any problems

 

If you are extending the O2 sensor wire use Thermo-couple wire.

 

I just went through this when I installed a invidia housing to my 9. Don't cut the wire and add a few inches. I did this and ruined my sensor, maybe because of the extra resistance. Two ways to do it, unwrap the harness and bring the cable around to the other side of the engine past the turbo or buy a new sensor, I paid $52 for the oem Denso replacement of Amazon. It has a slightly longer cable and can be run same as oem.

 

Have extended a few with no issues.

 

Not sure if Mitsubishi does the same thing, but I know on Toyota's the OEM O2 sensor's have RF shielded wires. They do not use conventional sheathing. Cheapie auto parts store sensor's (universal type) that you have to solder to the factory wiring have standard wires, & I've seen vehicles come into the shop I work at with a technically functioning sensor, but improper wiring is causing the sensor to throw a bogie code because of RF interference. Denso makes the O2 sensor's for Toyota, & I'm sure they do as well for Mitsu.. Probably the same type of wiring is used on both. My suggestion would be to avoid cutting/lengthening the factory wiring if possible!