Erich_870

Update 2:

The sound was getting louder so I got into the shop this morning and it turns out one of the O2 sensors was slightly contacting one of the heat shields. A small tweak and it was fixed.

Here are some pics:

I couldn’t see down the inlet side, but here’s what the catalytic core looks like stock. My replacement cats have a square pattern with slightly larger holes. I can hear a difference in the engine sound now, it sounds more “throaty”





Erich

CaseyJones

Alright so the good news is that I passed emissions here in Oregon! I ended up having the flanges between the cats and the pipe sections welded (it ain't pretty but it's functional) which hopefully addressed any leaking exhaust; I replaced the rear 02 sensor with a Denso; and I put on a new Flowmaster muffler since the existing one was separating at the seam and leaking a bit...(On a side note, I must have been getting some back pressure due to the crappy muffler, because I noticed much smoother shifting with the new one! Can't believe I waited so long to replace it)

Take home lesson here!!!>>>>I took this truck to several shops and all said I would need to replace at least one of the cats. I replaced the o2 sensor and my CEL is off and hasn't come back after 100 miles of driving, and I passed emissions....the shops are in the business of making money, and while I don't think these guys were trying to screw me, I think they were playing it safe and recommending that I do extra repairs that weren't completely necessary just to guarantee the light would go off. Do your homework, do what you can yourself, and start with the cheapest fixes and work your way up the line!

Now I can focus on some other projects I have in mind for the rig, mainly updating the suspension. Anyways, figured I'd post some tidbits that I learned from this ordeal that might be helpful.

1. As mentioned earlier, there is no difference in California and 49 state emissions vehicles from the 2001 tacoma onwards, i.e. they all have 2 cats! I can't tell you how many parts stores and repair shops either were uninformed or confused by this fact. I called a lot! I verified the info posted here by EnolaGaia with my local dealership.

2. It is apparently a federal offense to re-sell used catalytic converters, so the suggestion of finding a good one on a scrapped vehicle is only good if you know somebody who's willing to risk a $10,000 fine.

3. On my truck anyway, the plug and play clip/wiring harness for the rear o2 sensor is under the passenger seat and requires removing the carpet (at a minimum) and possibly the seat (if you have fat hands that aren't that nimble) to access and replace.

4. I wish I still lived in the woods where this wouldn't have been an issue, but I am glad I learned some new stuff, have a better understanding of the emissions system, and have a cleaner running truck.

Thanks for all the help!