Anyway to replace these catalytic converters without welding?

Story of the truck is the cats were stolen - the replacement welds are ass. Welds look terrible and they decorated them with JB weld to try to get rid of the P0420/P0430. I'm inclined to start with the cats in treating the P0420/P0430 because of the aftermarket cats and potential leak at the welds (one is Catco, other idk).

I'd like to get Walker 83460 and 83451 (CARB-compliant) cats given the support for them here. I need to pass a smog test. Unfortunately, one of the attachment plates is missing (near the muffler, passenger side) - so do I have to get someone to weld that portion for me? If so, how do I drive it to the shop? attach the driver side and let the passenger hang loose for a mile or so?

 

I see in the picture your bank 2 cat, bank 1 cat is obscured, and your resonator, no muffler.

Quick Q: Did the P0430/P0420 start before or after the cat theft? Only asking because there's another known issue that causes those codes.

Another Q: When they cut out your cats, did they damage any of the wires to your sensors?

Last Q: Do you have a scanner that can read realtime stats? Even some of the cheap $30 readers on scAmazon will manage it.

 

PS - the flange you're missing on the passenger side (bank 2), a new flange will come on your replacement cats, but you'd need to replace your Y-pipe or have someone weld on a new Y-pipe flange to meet up with the cat. Junkyard or parts truck listed on FB Marketplace or CL or something may be your best bet, to get a Y-pipe and resonator from a truck with the same cab type/engine.

 

Thanks for the reply. I've got no info about the truck except the general story before it was sold to the Pick-N-Pull, then picked-up at their auction by the people who sold to me.

I do have an OBDII, what is the other known P0420/0430 issue?
My plan is to research what to watch on the fuel trims and O2 sensor voltages (fill me in if you know), clean the injectors, check the spark plugs, EGR valve, etc. and start there before I order the cats.
Sensor wires look okay to the eye. Previous owner replaced the O2 sensors as well on the passenger side.

 

Start here: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

If you're smart, you'll read - not just glance over, or skim, but actually read - the first two replies. Yes, I published it (someone has to), but multiple members contributed, it's not my opinion in there, it's all the stuff this community felt any person new to these trucks would need to know about your new purchase. Including nuisance things like codes, common issues and their known solutions, red herrings.

The first thing you need to do is make sure your frame isn't rusty. Sometimes the rust is very well hidden. This reply covers a ton of it, it is also linked in that thread I just shared: https://www.tundras.com/threads/2003-sidestep-tundra-help.159044/#post-3935494

The baseline though is, these trucks are super picky with cats. Quite often cat efficiency codes in these trucks is a byproduct of (A) bad and/or counterfeit and/or cheap aftermarket upstream/downstream sensors and (B) exhaust leaks causing those sensors to get a bad reading.

 

Good advice from @shifty` above. Any exhaust shop can weld your new cat(s) on for you. They will cut and weld as needed. Do some research and find a good local shop that's reputable. Walker and MagnaFlow cats generally behave the best outside of OEM. O2 foulers may be needed for stubborn codes. Denso O2 sensors are the way to go. I've also had good luck with Bosch, but would likely replace with Denso on the next round if they fail.

 

Yeah, just don't buy your Denso sensors on fleaBay or scAmazon. I just saw someone on another forum that ordered theirs from scAmazon, and one from RockAuto. The one from scAmazon said "made in Japan" and was clearly fake, once you put them side by side. the one on RockAuto said 'assembled in USA' and was the legit one.

 

I'm going to go out and run a shop vac into the exhaust to check for leaks, then I'll check O2 sensor consistency after warming up @ 2500 RPM, then I'll simulate a lean state and see if the minimums are fine. If it's an exhaust leak, I'll just get a cat anyway because I don't want to run the risk of paying for new welds on sub-CARB aftermarket cats anyway.

Frame looks fine, even in problem areas, some dispersed surface rust I plan to go over with POR15 after sanding out.
I think I'll just pick-up a Y-tube along with the cats to enable disassembly if needed in the future. It's about the same price/cheaper than the weld quotes I've gotten, unfortunately.

 

If you've never used POR15 before, what you're proposing isn't the proper or best way to use it. Share some pics. And if you choose to ignore this, forewarning: Wear gloves. That shit won't come off for weeks. I used it a lot, as have quite a few others on here.

We had a really killer frame show up recently. Looked fairly mint everywhere, on the long runs, etc. Hell, just look at the area around this ...

But nope. Multiple rust holes straight thru the frame in one of the notorious spots where nobody seems to check. Even people who look in the megathread which gives you all the rust locations to watch out for, some with pics, they read that and still miss it. We've seen frames cracked clean in half in this specific spot.

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Cool - thanks. I'll make a separate thread when I think about tackling the rust. Fortunately none in the spots of concern, including that pic Currently, getting it registered then handling the suspension are priorities 1 and 2. Frame + cab rust spot treatment 3. Bed rust 4.

 

Confirmed that there are a couple exhaust leaks at the welds. Going to replace the cats and go from there.

 

Exhaust leaks will most definitely cause 430/420 codes. Maybe just get some muffler tape/goo at AutoZone and seal up the leaks to see if your codes go away? I'm not advocating this a permanent fix, only a quick and dirty way to confirm/eliminate the cats. I did this when the flange rusted off one of my downstream O2 sensors, causing it to throw a code. The muffler sealing goo (actually JB Weld Muffler putty) stopped the leak, and eliminated the code until I could get to the muffler shop and get a new flange welded on.

 

This was my thought also.

@xaq you mentioned you need to pass emissions, and I'm sure it'd be nice to have the added bandwidth (financially, timewise) to do this the right way.

Before replacing the cats - even with thse nasty-ass booger welds, why not drop $20-30 on high-temp exhaust repair tape, tape off the spots you know are leaking, then smoke test to look for others to potentially tape, then go from there?

If it solves your issue, great, go get tested, pass emissions, and start hunting for a new Y-pipe and maybe some bolt-on-ready cats from Walker, Summit, Magnaflow? (Ideally CARB compliant, to avoid code-popping).

 

I think that's a good call, I'm not super concerned about time. Should be a quick repair, and I have another truck I'm not selling until I get the Tundra up to snuff. Got everything I need, including the resonator Y-pipe, from Rock Auto for $1,300. Tough, but figured I'd be sinking in $2,000 between the exhaust and front end to get this thing back to ideal.