I also agree that the Cerakote coatings are some of the best and we use the Glacier black for our ceramic coatings.

GESI cats are also a top choice. We use them on out 200T downpipes and have used them on M4 downpipes too right after the turbos. They are very durable and efficient.

But the circuit works on current, not voltage. I participated in the DIY wideband project, so I'm pretty familiar with the electronics involved in a wideband sensor. If there's any way to avoid an extension, I would work hard to figure it out, especially if it involved splicing wires together to create an extension. Each splice brings its own spice to the party, and while the heater element won't care a whit about it, the pump circuit will, and the lambda accuracy is all about the pump circuit.

Can you extend it? Sure. It just won't be the same as the original configuration and may present weird issues.

I totally agree with not placing the wideband in a single tube. That's inviting disaster or expecting to live a charmed life.

Thanks a lot for your input on this thread! So if I'm understanding you correctly, your EL (equal length) header comes with a "bung right after the collector" that would allow me to extend and place the wideband sensors in their proper place (avoiding the stupidity of placing them on a runner). I hope I got that initial point right. Lance point related to this, is that extending these cables for those primary sensors could bring a multitude of issues that he explained, and that I in theory concur with. He says however that it can be done, but that he would rather avoid it (which is his main point), or only do it as a last resort; I concur with that as well. So, lets shelve that issue for a second if you don't mind, and go back to why I started this thread which I'm so lucky as to have you and Lance responding, please keep going!

I have a 2018 GS-F that I track. It has deleted secondary cats with a high flow aftermarket (cat-back) exhaust. In order for me to do headers (as a mod for power) the primary cats will have to go, unless I go the Novel route. I rather not, and buy the EL headers you make since I think they will "produce" more power than Novel and are much more reasonably priced. Lance mentioned that he would add GESi cats to deal with the odor, which I concur with. Then comes the issue of the CEL or the ECM not liking the readings of the sensors before and after the primary cats (even if they are gone). If you have a 2016 GSF, RR makes a tune that you can use to "tell" the computer that everything is OK. But RR has not been able to do the same thing for 17 and 18's. Therefore, in order to keep the CEL off, I have to use a sim or something of that nature, or have properly placed GESi cats in the system with the sensors at the right locations. I totally got and agree with your point of: "Because of this, simply moving the downstream sensors after your cats that are 3-4 feet from the collector will not keep the CEL off." So, I agree that for the GESi cats to do their job WELL ENOUGH for the computer to be content, they will have to be super close to the collector to get the massive amount of "heat" that they need to function efficiently enough. That said, do you know of a simulator or a device that will keep the CEL off? The ideal thing is the RR tune, but we are not there yet. If I could have a device that will accomplish that (CEL off), I could then have your EL header (with Cerakote), add GESi cats to the system and place them at the OEM secondary cat location, and most importantly have no CEL problem. Can youo answer this and then we could deal with the issue at the shelve?

Option 1:
You could put the GESI cats in the secondary cat location and then use 90 degree O2 sensor extenders on the secondary O2 sensors. This should keep the CEL off and the cats can still help reduce the emissions/exhaust smell.

Option 2:
You could put the GESI cats right after the headers in the midpipe and then relocate the O2 sensor bung after the cats and angled backwards so the wires will reach. The bung will have to be extended about an inch and angled backwards. The cats would work better in this location (hotter), but they will decrease your ground clearance and may hit speed bumps if your car is lowered.

(I would go with option 1 myself)

So I had to be sure... so I raised my whole car and spent more than a few hours underneath it (no beers or music involved of course thinking and plotting about this whole thing for the last 2 days... So, the first "mistake" or lack of foresight from my part was that the OEM location for the secondary Cats is full of clamps and hardware from the GT-Haus mid-pipe, as it comes in two separate parts that join together at that location; unlike the OEM counterpart which is one solid contiguous assembly. So to do this, I will have to do some precision cutting and TIG welding (which is not that trivial) to turn the whole thing into one long solid part, as OEM does. On top of that, not only would I have to extend the cables of the secondary O2 sensors using the "90 degree O2 sensor extenders" that the gentleman from PPE Headers was alluding too, but more cutting, welding and patching to "move" the secondary sensors from their current location (high on the mid-pipe) to downstream from the GESi cats at the secondary cat location... I get exhausted just thinking about it, hahaha.

Not to open a can of worms, but a quick note on the cables before moving forward: Mr. Lance... Am I correct sir that your concern (which I share) based on your own experience with those cable extensions, refers primarily to the wideband (primary) sensors and not the secondary? If correct, would you be equally concerned with extending the secondary sensors?

At any rate (and I think that he was referring to the primary sensors) it is a lot of work guys..! Hahaha

So Mr. PPE, clearly it will be a lot easier to just get the headers and put some "sim" or "tune", or some other "device" that will keep the CEL at bay, and off... And if the smell (or the sound) gets too crazy, I'll just add the GESi cats at the secondary cat location and call it a day. So, do you (or anyone you know) or Lance, or anyone else reading, knows of a device that is available for purchase that will do such a thing? That is why I have been waiting for the RR tune all this time... obviously not for 6HP that you can get from it. Frankly, I rather have a "sim" or a "device" that will keep the CEL off independently from the Engine ECM's as I'm a Techstream user and will not like to loose my ability to upgrade calibrations by sending my ECM to RR, if you know what I mean.

The wideband sensor is the only one I would be concerned about. The O2 sensor that sits post-cat is a conventional O2 sensor, so it will be a lot less likely to be problematic if you extend the wires. If you want the details of why I get spooked by the idea of extending the wires, read through the attached doc on O2 sensing, and notice the "recommended" current value is 40 microamps. That's not a lot, and adding resistance, even small amounts, will change the characteristics of how the sensor performs. It won't quit working unless you make bad crimps or introduce really big resistive values, but the ECM is comparing what the sensor sends it with values plugged into a table of expected performance. When they don't line up, you get a CEL for a bad sensor. It would really suck to go through the whole adventure, plug everything in, and have that piece of it decide it's unhappy. That's all I am saying.

LOL!! Oh my God I agree 110% that it will really suck if after all that work the CEL is giving you crap! That is why, It will be in my interest to have the "device" that I speak about... a "sim'' a "tune" or something of that nature as a primary way of keeping the CEL off; or as a back up if I go the GESi route and still have issues…….I Imagine you wouldn't know how to build one of those little things do you, Lance?

At any rate, based on your confirmation here related to the secondary sensors (not a sure thing, but more likely to work than the primary sensors) and that of the PPE Header Gentleman (his "#1" suggestion from his last post)… That suggestion will be logical and reasonable, and the way to go if one was looking to use the GESi cats as a way to keep the CEL off in conjunction to keeping the smell (and in my case the noise) down. One of the last questions to ask and one that he alluded too (I don't know that it can be answered here) is whether there will be enough "heat" present at the secondary cat location to make that GESi cat "efficient" enough to meet the spec of the ECM as measured by the secondary sensor.

By the way Lance, thanks for the reading assignment, I'll try to go deep.

Guys-

Been away and did not have the courtesy of closing this chapter, for those of you that might care. The deal here is that the complexity of building a simulator that could actually keep off the engine ECM is not trivial if one was to use the PPE header. The secondary possibility of moving the sensors to "better locations" is also non trivial. One risks the CEL coming on one way or the other and I should not have to explain the effects of that condition and why it could negate whatever gains were accomplished by using better headers than OEM. I know RR and PPE are working on the tune that could amongst other things fix this issue, but we are not there yet... The only possibility left would be to use the very expensive Novel header with its integrated CATs, but no one was able to show performance figures for that header so if you are looking primarily for power gains more than for sound, it looks that we are stuck for now.

Special thanks to Lobuxracer and to PPEHeaders for spending their time and efforts on this interesting conversation.