o2 sensor extension

[whafam]

I have the coyote gen 3 in my roadster with the FFR headers. The wiring from the PCM obviously is not long enough to reach the LH or driver's side as has been noted in another post I saw. I have seen where some have purchased an O2 sensor extension, but I personally cannot find where to get one that is 24 inches in length, at least that says it would fit the Gen 3. American Muscle says the only thing for this engine is 8 inch extension. Has anyone cut and spliced/soldered and had success? The Ford instructions say not to, as it may affect the sensor performance and signal reliability. In trying to separate out the UEGO legs, there is a common power wire that has to be cut anyway in order to gain extra length on the LH side. If there are posts out there about this already or if someone has experience with it, please let me know...and if so, how to you route the wiring for the LH/driver's side? I apologize but haven't found much on it. Thanks in advance!

[edwardb]

I personally haven't used them. But the purchased extensions I've seen mentioned on here repeatedly are from Caspers Electronics. This is their Ford listing. Haven't checked compatibility with the 2018+ Gen 3 sensors. http://www.casperselectronics.com/cart/index.php?route=product/category&path=7_45.

I know it says not to in the instructions, but I've extended the sensor leads on both Coyote installations I've done. Including the Gen 3 in my Coupe. The supplied Control Pack harness is ridiculously too short. I'm not sure what they were thinking on that. What's important is the following: Don't try to extend the pigtail on the O2 sensor itself. It's something other than regular copper stranded wire and hook-up wire insulation. But extending the Control Pack harness leg has not been a problem on both builds. I pull back the convolute, cut the wires some inches away from the connector, and then splice in wires to extend as needed. I solder and use shrink sleeve over each splice, and then install convolute for the new length. Done properly I see no reason why it won't work, and in fact has been fine for now multiple driving seasons.

[whafam]

Thanks so much! That's what I was sort of thinking, that the O2 sensor itself shouldn't be disrupted, but the harness would be ok. Cutting into the harness to remove the CMS 4 wire plugs just revealed normal copper wiring. I have sooo much extra wire, I may just make my own extension! Thanks again for the information, and especially for your build threads, as I tend to look through them when I have a question!

[steno]

EXACTLY as Paul said. Modify the chassis harness. NOT the sensor assembly.

[Dave 53]

On my 818S build, I cut and spliced in a o2 extension. The data wire (between the sensor and ECU) must be shielded. Other than that, was easy to cut, splice and shrink wrap. When you cut the wire, you'll see the shielding. I found shielded wire on line no problem.

[steno]

For those who need shielding a splice, get cheap aluminum foil and cut into strips, and wrap it up! Works great!

[edwardb]

There's no shielding in the Ford Performance harness runs to the O2 sensors. Just plain hook-up wire inside the convolute.

The actual O2 sensor pigtails are some kind of special wires and have (I think) mainly a heat shield piece around them. But don't disturb any of that as already suggested.

[BradCraig]

Ditto...extended the harness not the O2 lead. It's fine, just do a good job soldering.

[BEAR-AvHistory]

Bought custom length units with matching plugs. Were under $20 about a week turnaround. Will try to find my receipts if anyone is interested.

[whafam]

Thanks to all for input! Personally, I think I will extend the supplied harness since I'm into it anyway and have so much wire laying around from a couple projects:)

[olson_adam]

I no plan to do the same ... just extend the harness