P0420 on my wife's 2003 corolla

[demonfire]

So i'm @ work and i get a call on my cell from my wife asking why this light came on in her dash, and what to do... so i go thru the basics "is it blinking?" no. "okay dont worry about it i'll scan it tonight."

Turns out to be P0420, catalyst efficiency below threshold bank 1... which normally means the cat is on the way out the door. However, the car is an 03 CE with 103k on it, and this seems fairly premature, doesn't it?

Couple questions - is the cat one of those annoying close coupled part of the manifold design, or is it something i can cut off a piece of pipe then weld in another?

Thanks in advance for any replies.


edit - btw, this was about a month ago. I turned the light off and it came back on, so i'm not sure if it's just a fluke. Actually, i haven't even scanned the new light yet, (came on yesterday) but i am fairly certain this is it. and is it true there is no servicable fuel filter?

[ghost_ryder35]

Originally Posted by demonfire

So i'm @ work and i get a call on my cell from my wife asking why this light came on in her dash, and what to do... so i go thru the basics "is it blinking?" no. "okay dont worry about it i'll scan it tonight."

Turns out to be P0420, catalyst efficiency below threshold bank 1... which normally means the cat is on the way out the door. However, the car is an 03 CE with 103k on it, and this seems fairly premature, doesn't it?

Couple questions - is the cat one of those annoying close coupled part of the manifold design, or is it something i can cut off a piece of pipe then weld in another?

Thanks in advance for any replies.


edit - btw, this was about a month ago. I turned the light off and it came back on, so i'm not sure if it's just a fluke. Actually, i haven't even scanned the new light yet, (came on yesterday) but i am fairly certain this is it. and is it true there is no servicable fuel filter?

well with 103k on it its not to pre mature for the cat to go, and it is true, the fuel filter is now around the fuel pump its self, and they claim it never has to be serviced, unless you replace the fuel pump.

[demonfire]

Thanks for the reply. Is this an item that the corolla people would have used for a good price (people who upgrade to "race" headers, and / or off road pipes) or is it something i have to get from a dealer, or online?

[daniel2002p]

I am not sure about this but dunno how lucky u will be finding a used one, correct me if I am wrong but I think the law doesnt allow the cats to be removed unless they are busted....

D

[demonfire]

That's correct, you're not legally allowed to remove a working catalytic converter - but people pull them off and replace them all the time with performance units. Like i said before - i'm not sure if the corolla crowd does that as much, and i really haven't looked too hard at her exhaust system (car's been too reliable, i suppose, so that when something actually DOES go wrong i overreact).

lol

[dLo914]

i always thought that Bank One referred to the O2 Sensor before the cat. I'm prolly wrong but it was always the diagnosis when i use to work at Autozone for the past 2.5+years.

[demonfire]

Bank 1 versus bank 2 refers to V motors (like a v8, v6, what have you) where you have two banks of cylinders. on a 4 cyl car (sans flat motors like subarus) you only have one bank, hence bank 1. the first o2 sensor gives ECU feedback for air/ fuel mixture, the second only monitors catalytic converter function.

[ghost_ryder35]

dont know of any used cats laying around. Check out www.rockauto.com or www.ebaymotors.com , good luck. p.s. did you check to make sure its not just a fault O2 sensor? I would do that before replacing the cat!

[gbell210]

I had that code in my '00 Corolla. After a month of resetting it after about each 40miles, I finally found a shop to weld in a new (cheap) cat for about $130. Fixed my problem and it hasn't come on in about 4 months. Only thing is on deceleration, it sounds like something rattles at certain RPMS. Only thing I figure is something in the Cat, because I took it back to them and put it on a lift and looked for loose heat sheilds and whatnot.

[demonfire]

Honestly i have not checked, but the second o2 sensor would throw a different code, in my experience.

Thanks for your help, guys. I'll check rockauto (got some parts from them for my xr4ti) and ebay as well.

oh, that reminds me, another question - are there high flow cats available, say, thru random tech or another similar company?

[demonfire]

My wife's 2003 Corolla CE which has 105k on it keeps pulling a P0420 catalyst efficiency below threshold bank 1, which means time for a new cat. I looked around online and got a couple prices but the pictures (that may not depict the actual part) show what looks like a normal universal cat, which i can pick up for waaay cheaper than they want ($365). If this is the case i can simply measure the cat and get the replacement for under $100, and weld it in myself. I'm worried it's something silly like the focus design (specifically the SVT design) with some goofy shape, or worse, like the SRT4 with it integrated into the exhaust manifold. Granted, i've seen the manifolds for $140 so i dont think that's the case.

No - i'm not going to get a cat delete pipe and will only consider a high flow if it's cheaper than the oem replacement and if i can not make a universal fit.

Thanks!

[ghost_ryder35]

you can usually get them on ebay for dirt cheap, but my expierence with those is you get what you pay for, replaced two of those supposive "high flow oem fit" ones. then i ended up going with an aftermarket brand name from auto zone.

[demonfire]

Yeah i think i'm going to go with a magnaflow high flow cat, high quality, stainless, etc. Plus i can get them for lik 80 bucks.