rowdy235

Came off the freeway today drove a couple miles and the CEL came on. Stopped by the local autozone and they pulled the codes and found P0420, something about the catalytic converter effeciency being low. Thought it was just a fluke so I cleared the code and the CEL hasn't turned back on yet.

Now, I'm worried that the CEL will come back on, probably sooner rather than later. I'm wondering what is the best route to go when replacing it. Stock converter is in there now, but I don't even want to look at those prices. Anybody running an aftermarket, and if so, how does it work?

Thanks.

FogRunner

Going with an aftermarket cat is a mixed bag. I know several tacoma and runner owners that have gone with aftermarket only to have it throw a code 6 months later.

That being said you have three choices. You can go with a new factory cat which is VERY expensive but will have a long life. You can go with an aftermarket which will not last long and you will have that P0420 code again real soon.

Or you can go with the O2 sensor simulator http://www.urdusa.com/index.php?cPath=66_170 It goes inline with the sensor and "modifies" its output to make the computer think its working at full efficiency.

I had to install one on mine 2001 Runner. Now before I get blasted by the environmentalists. My emissions are above my states standard (Texas) as per the treadmill and tailpipe sniffer. The problem is in 2000 or 2001 Toyota went 50 states legal so they made all their vehicles CARB (California) compliant. So even though my yota is meeting my states standards its throwing a code because its set for California standards.

Basically what they did is set the computer to throw a code if the cat efficiency gets below 95% to throw a code. In comparison other no CARB compliant vehicles throw a code if the cat efficiency gets below 75% IIRC.

But back to the aftermarket cats. If your vehicle is before 2000 and none CARB compliant you can get 6months to a year on most aftermarket cats. But as far as CARB compliant yota, I've seen several people that tried aftermarkets cats and even brand new wouldn't meet the efficiency standards and would throw a code.

FastOlds

When they say "very expensive" they aren't lying. list price on a CA emissions cat for my 2.7 4runner is over $1700 from the dealer. And none of the aftermarket places sell a direct fit replacement. and where i work, i've seen too many universal ones suck royally. In my case, I'm hoping that the in-laws are willing to help with a new one.

rowdy235

Thanks for the responses. CEL hasn't come back yet and hopefully it won't.

There ain't no way no how I could put an OEM one on there. Its impossible. I will probably go with a magnaflow and then if the light comes back on get a stimulator.

43jeeper

For what its worth, I had the same CEL and code, and searched and read and chased around the idea of a new cat and then a new O2 sensor, which is really whats at fault, unless your cat is really going out. Mine isnt. In the end I simply disconnected the first O2 sensor, before the cat. Didnt get rid of the CEL but my mileage has gone back up to 19mpg, from 15mpg. Good enough for me.

86tuning

Heh, buy a cheap code reader and clear the codes each time until you get sick of it. Then change your cat