So, I've started to get a C.E.L. come on at random times when driving. I've had the code checked and it's a p0420 catalyst efficiency code. If i reset the ECU it goes away but I was driving out of town, and it came back on. I've reset it once again but thought I'd appeal to the infinite knowledge of my fellow Scionlifers.

I've done a little research and noticed that there exists a federal mandate that catalytic converters be warrantied 8 yrs, 80k miles. Does anyone know if this is true of Toyota OEM converters? Maybe someone who works at the dealership might now, or anyone who's also encountered this C.E.L. foul.

Thanks guys/gals

~F

 

quick google search returned this:

This code is generic and is the same on all vehicles.

P0420 = Catalyst System Efficiency Below ThresholdCatalyst System Efficiency Below Threshold.

This means that the secondary O2 sensor detects that the catalytic converter isn't working as efficiently as it should.

This engine code can be triggered by any one of the following:

1.) The catalyst in the catalytic converter is cracked, clogged, or otherwise damaged.
2.) The secondary O2 sensor is malfunctioning.
3.) There is an exhaust leak.
4.) The computer unit is faulty

i would look into getting the second O2 sensor checked (its the one in the S-pipe under the engine)

 

Do you have a header or anything like that on the car?

 

if you have an aftermarket header it might be that. I have an 02 sensor anti-fouler if thats what it is for $20.

 

no aftermarket header, and apparently due to the code, it indicates it's bank one, which would be closest to the header itself. I have no idea, however, in my own research I found someone who had used a lucas cleaner in their motor, and all the crud that came out blew his Catalytic converter out.

I've done this through jiffy lube a couple of times, anyone think that might do it?

~F

 

That is why I wont use any of that stuff. There always seems to be some type of negative effect on it. Good luck with the issue. Let us know what it ends up being though please.

 

I will, there is a federally mandated 8 year 80k mile warranty on Catalytic converters. I have to take it in to verify it's not the O2 sensors faulting, but it's still $89 dollars just to diagnose. Bummer, but if it IS the cat, I don't have to pay for the diagnostic fee.

::rossing fingers::: I'll keep everyone informed. I think I am going to take it into the shop on Sat.

`F

 

It may just be an 02 sensor went bad.i would find someone to swap 02 sensors with you just to test it.

Now if its your cat,thats a another story.i doubt it blew up because it would more than likely fall apart and little pieces would get sucked up into your block causing it to blow.Some cars have recalls like that called pre-cat failure.

Let me reaserach it a bit more and maybe i can save you some money

 

what grade gas do you use and how many miles on your car?

 

Supreme Chevron/Techron, (92), never change that, and I have 60 K on it, car is religiously serviced on time.

 

damn! why are you running that? our cars run on 87, factory recommended

 

i run 89.

87 kills 02 sensors.

and 92 may be a bit much i think

how many miles do you put on the car daily?sometimes your cat needs to warm up from a long drive so that way it can burn up cold gases.when you just make short trips it tends to stay cold and will thow a code every now and then.

 

I've always used premium octane in all my cars, and the last two were toyotas without any problem.....

 

Alright, official dealership diagnosis is a crapped out converter. Looks like the Fed. warranty is going to make this one quick and painless. Thanks for all the input folks.

 

good to hear