P0420--Cat efficiency low bank 1?

[ZY100]

Hi,

01 (fixed typo!) PT Cruiser, auto, non-turbo, 73K miles

Getting above error code, with--accordign to autozone computer--four possible causes; 1. Cat converter defective, 2) Engine misfire, 3) Large vacume leak, 4) Engine oil leakage past rings.

- Reset it 3 x still comes back on in about a day
- replaced plugs, wires look good
- car runs good
- no oil consumption

Any thoughts on what I can test/check at home befoer bringing to the dreaded dealer? Any way to test the cat?

Thx
ZY

[JoeHundredAire]

Originally Posted by ZY100

Hi,
- Reset it 3 x still comes back on in about a day
- replaced plugs, wires look good
- car runs good
- no oil consumption

Any thoughts on what I can test/check at home befoer bringing to the dreaded dealer? Any way to test the cat?

ZY

There's no way to tell what condition the wires are in by looks. If they are the original mopar wires, then go ahead and replace them.
As far as testing the CAT I'm not sure if there is a way to test it without special equipment, but I'm sure there is something.
Given that you said it's running fine, but it's possible that it's a bad sensor rather than the CAT itself. Typically you can test the O2 sensors with an Volt/Ohm meter. Of course, I just replaced the CAT on our '01 Celica & it was running perfectly fine as well. So even if the cat isn't doing it's job, doesn't mean it's hampering performance. Either way if it's a bad sensor or a bad cat, I wouldn't take it to a dealer for that. Find a cheap muffler shop & have them replace the cat. It'll be alot cheaper than a "stealership".

[CREWZIN]

Welcome to the forum.

What year did you say your PT Cruiser is ....91 ????

Anyway, here's something to read about your fault code P0420...

Troubleshooting P0420 Catalyst Code

[Hooligan]

Aren't Catalytic Converters covered under longtime warranty under Federal Emissions?

[ucantcme]

I traded in my 91' because it had the same problem, lol

Just messin'! Welcome to the forums - Hopefully you can resolve this code quickly!

[air4cefamily]

My '88 did the same thing. I just bought a newer one.

[pdbrains]

Get or make a O2 simulator, after you install it and your code goes away then you know the Cat is bad and needs to be replaced.

[ZY100]

Thx Guys!

It was the CAT and it was covered under the 8yr/80K warranty! And I was at 77.3K, so your info was just in time.

However, as it was there and the timing belt was making nose, I had them do the belt, pully upgrade and apparently a new cover....got me for $1K.

Wow....I probably could have found a local garge for ~600, but they had me by the curlies. I took the path of least resistance and let them do the belt. Boy, I do hate the delaers though.

ZY