Toyota Tundra Cat question

[wdfifteen]

According to the dealer my 2003 Tundra needs a new catalytic converter on the left side. Price for the converter is $800+ and we didn't even get to the labor charge.
Flowmaster has a bolt-on cat for $289. I called a couple of shops, but they will only install their own $749 units or the genuine Toyota part.
If I buy a Flowmaster and bolt it on myself, will I have to have someone reset the codes or something to get the check engine light to go off? I don't know squat about OBD systems, but I'm afraid I'm going to have to bit the bullet and learn.

[A930Rocket]

A $50 reader from Autozone will read and clear the codes. Buy a mig welder with the money you save having them install it and do it yourself.

On a side note, we used to remove the cats, take the car to the shop and tell them "to fix the leak".

[IROC]

Are you getting a P0420 code? From what I've learned on my Tacoma, a P0420 code ("catalytic converter less than efficient" or something like that) is a result of applying CA emissions standards to the other 49 states. In other words, cat operation that is somewhat less than what is considered good for CA is just fine for the rest of the country. It's a non-issue on 49-state vehicles. I've heard second-hand that Toyota dealers even tell people not to replace the cats in this situation.

Also, I've read that you've pretty much got to use Toyota cats. Anything else will simply result in more P0420 codes.

I bought a code reader (they're cheap) and just reset my P0420 when it pops up.

Now, if you've really got a bad cat, that's a different story, but even then I think you're looking at biting the bullet for the Toyota cat.

[wdfifteen]

They didn't tell me the code number but they did say the problem was "catalytic converter less than efficient." Thanks for the info about aftermarket cats. How often does the code appear on your truck?

[onewhippedpuppy]

Originally Posted by wdfifteen

They didn't tell me the code number but they did say the problem was "catalytic converter less than efficient." Thanks for the info about aftermarket cats. How often does the code appear on your truck?

Sounds like you really need an OBD code reader. I bought one at Harbor Freight for all of $40, it's worked fine for several years now. Depending on the code, sometimes you'll get cat related codes due to vacuum leaks, failing MAF, O2 sensor, etc.

[t-tom]

My 01 Tundra has the TRD cats and exhaust on it. Its thrown that code and the o2 sensor code since it had 20 miles on it. I just don't look at the light. I'm going on 200k on the truck.

[wdfifteen]

Man, this place is a goldmine of information. Just picked up the truck and the service invoice states "Code P0420." So - I think I'll put a piece of black electrical tape over the light.
I'll go ahead and buy a scanner and check it every now and then to see if something else has gone haywire.

[jcommin]

Don't let the shop keep you old cat. You can sell it - it is worth some money.

[sammyg2]

Originally Posted by jcommin

Don't let the shop keep you old cat. You can sell it - it is worth some money.

In Kalifornias it's illegal to sell a used catalytic convertor.

Doesn't mean it doan happen .........

[onewhippedpuppy]

Originally Posted by sammyg2

In Kalifornias it's illegal to sell a used catalytic convertor.

Doesn't mean it doan happen .........

You can't take it to the local recycling place? You'll be mistaken for a meth head that just hacksawed it off of a parked car, but they are worth money for recycling.

[jcommin]

Originally Posted by onewhippedpuppy

You can't take it to the local recycling place? You'll be mistaken for a meth head that just hacksawed it off of a parked car, but they are worth money for recycling.

Absolutely!

[MysticLlama]

Another possible option is a spark plug spacer for the O2 sensor. Sometimes it takes the O2 sensor just enough out of the airflow to think it's cleaner but still pick up enough to not trip out.

[Joe Bob]

Also in CA, you have to use a cat that has a CARB executive order number on it. Check with your local smog people if you still need inspection and/or oem or equivalent replacement.

[IROC]

Originally Posted by wdfifteen

How often does the code appear on your truck?

In the winter time it will throw the code about very two to three weeks. I simply reset it. Strangely, my check engine light hasn't come on in months. It must be a temperature thing... At no time is there any drivability issues, I might add.

To pass on more of the story as I understand it, CA emissions regulations requires the cats to operate at 95% efficiency or above. 49 state is 80%. Toyota got tired of manufacturing two different setups (related to the catalytic converter configuration) and so they went to the 95% setup for all 50 states. So...you'll get a check engine light (P0420) code when the cat drops below 95%, when in reality (depending on how you define reality), 80% efficiency is just fine.

Having said that, the way this "efficiency" is determined is by comparing the output of the O2 sensor before the cats and the one after, so...it is possible that you have a bad O2 sensor as this will also throw a P0420 code. I replaced my front O2 sensor and it didn't help and decided to not replace the rear one...

[wdfifteen]

The shop said they tested the O2 sensors and they are functioning correctly. I wonder what kind of signal o2 sensors emit and whether it could be mimicked by something else. The computer is probably expecting it to change with temperature or something, not a steady signal.

[wdfifteen]

I think I found a low cost solution.

[coldstart]

It is a common problem with Toyota. My girlfriend's 2003 4-Runner SR5 (V8) has a serious sulfur smell on hard acceleration. I put a spacer on her second O2 sensor so the check engine light (CEL) would go off.

To replace the OEM cats in Canada would cost over $2K installed.

[IROC]

Originally Posted by wdfifteen

The shop said they tested the O2 sensors and they are functioning correctly. I wonder what kind of signal o2 sensors emit and whether it could be mimicked by something else. The computer is probably expecting it to change with temperature or something, not a steady signal.

Believe it or not, there is a company that sells this very item:

Rear Sensor Simulator - Underdog Racing Development