Yet another P0420 code

I don't think so. I know OP was able to remove the oval off some old sensors to make his spacer. I don't think it was threaded. I think he pried it off.

 

I had a couple spare rear 2 bolt flange o2 sensors laying around (you could possibly find a pair of the flange style o2 sensors at a Pick-n-pull?). The o2 sensor itself is welded to the flange. I ground down the weld far enough so that i could simply pull out the sensor from the flange with my hands. The whole process went WAAAAAY easier than i thought it was going to be.

 

Still no CEL?

 

No CEL yet. I took the truck to the DMV a couple days ago and finally got this cali based truck registered and titled in oregon. Now that all the paperwork is completed i don't really have a need to drive the truck around until i have a use for it. I have other vehicles that i drive around that get MUCH better fuel economy!

 

Try to unscrew that portion off the 90-deg angle portion and move it to the straight tube. It looks like it's just a simple thread-on and thread-off part.

OP's solution is different since he didn't buy a kit but instead did it the manly way and made the spacer himself. You and I don't have those capabilities so we had to buy the kit. The kit that I got looks identical to yours and I could thread on and off the second oval flange and move it onto the straight tube. If that particular kit from Walmart doesn't allow you to do so, then toss it and get the kit from J car parts or something.

 

Ok so I ended up taking the tube part you circled on the bottom right and using just it and the 2 ovals. The problem was not shown in the pic, but the tubular piece actually is threaded much longer and sticks out past the oval once threaded on. That made it not want to fit on the exhaust flange. So I had to cut the excess thread (~1/4") off with my band saw. Got everything on now. Hopefully no more issues. I have a feeling I'll be removing them again to be welded together. I don't have a lot of faith in just the threads. Also might get some new nuts and bolts that all match, because I used random miss matched ones I had on hand.
Wondering if I should've used tephlon tape on the threaded spacer parts.

 

no need for teflon tape if you use gaskets on the flanges

sounds like you got it all bolted up, just make sure the mismatched nuts and bolts are really tightened down

just curious instead of cutting down the threads, could you have used the nut included behind the flange on the right-angle joint? This looks like a nut you couldve used on the threads (like a spacer on the spacer, so to speak) so the flange would sit right at the end of the threads.

 

Probably. Didn't even cross my mind. Honestly I was wondering what that nut was for

 

At least you had an excuse to chop something down, always a fun thing.

 

Yeah I don't know how to weld, but I can chop some shit

 

that’s what she said

 

I'm happy to report that after modifying my o2 spacers, I drove around checking my Scangauge2 every 20-30 miles for a few days, but it kept saying "not ready". Finally hit 100 miles since I cleared the p0420 and p0156 and all monitors are finally in "ready", with no CEL. So I'll be getting the truck inspected tomorrow. It's been just over a two year fight with the CEL, since I bought this junker. I've replaced both cats twice and all four o2 sensors, 2 coil packs, 8 injectors, 9 spark plugs, a cam position sensor and finally 2 o2 sensor spacers.
Not to mention the handful of non CEL related repairs. I think the beast has finally been tamed!

Thanks for all yalls help @whodatschrome @DarkMint

 

Good luck at the inspection tomorrow! And hopefully this thread won't go beyond 5 pages long.

 

Passed!

 

Well two weeks later and probably 3 tanks of gas, I'm sitting at a light tonight and the CEL fires up. P0420 & P0430 are back. Fuck. I already passed inspection, so fuck it. I just deleted the codes. That not my problem til January 2025.