Catalytic is coding

[chanwmr]

One of our 07 Libbies' engine light came on. It's my kid's and she's away in college. She took it down to her local shop and they said both cats need to be replaced. The quote is over $2100. It has roughly about 115K on it. So, it's still somewhat of a baby.

Is that quote about right? What would you do? Get more quotes and opinions? Drive it till the next inspection then get rid of it? Or, get it fixed, either here or elsewhere?

 

[JasonJ]

Assuming the diagnosis is correct? I'd find some cats off of a junk yard donor...

But I'd get a second diagnosis to confirm from another technician.

What codes did they find stored? What other tests and diagnostics were performed to come to this conclusion? If they're just going off of a Bank 2 catalyst efficiency below threshold code... well.. I'd be suspect.

How's it running otherwise?

 

[Aceofspades]

What was the engine light code ?
Sounds a bit overkill. Probably just needs new o2 sensors if they are replacing the cats

 

[Royy]

IF it indeed turns out to be the cats, you can get aftermarket ones for about $350. Of course they won't be as good at filtering as the OEM $1000+ ones, but as far as the Jeep's performance goes that makes no difference.

Assuming the diagnosis is correct? I'd find some cats off of a junk yard donor...

Can't get cats at a junkyard. Federal law makes it illegal to sell used cats.

 

[tommudd]

I'd get a second opinion for sure, rare that the cats are an issue at that low mileage, but still possible
Price is about right for OEM, and the only way to go. Aftermarket cats do not flow nearly as well as stock ones do. Would never use aftermarket
( of course off the record, could find someone selling parts on Craigslist and grab the whole exhaust may or may not be good , but I never would suggested that :emotions34

 

[tommudd]

IF



Can't get cats at a junkyard. Federal law makes it illegal to sell used cats.

Yes correct

 

[JasonJ]

Can't get cats at a junkyard. Federal law makes it illegal to sell used cats.

Yeah... but I know some people who know some people who would trade them for a case of beer. :happy160:

 

[Aceofspades]

I also see on Craig's list people parting out jeeps before the junkyard. IF that's the case maybe you can score a cheap set that way too. But I think its something else. Post the codes and seek a 2nd opinion

 

[renegade 04]

I would first replace the oxygen sensors before you replace the catalytic converters just to make sure.

 

[HoosierJeeper]

What are the codes? So many things could be wrong that actually aren't the cats. Have her take it to Autozone or something and get the codes read.

If it's a PO420 then that's most likely the cats. But anything else is really worth investigating.

 

[tjkj2002]

I would first replace the oxygen sensors before you replace the catalytic converters just to make sure.

If it's those P0420/P0430 codes you must have operating O2 sensors for those codes to set.

You can not fix those 2 codes with new O2 sensors and you can't clean cat's regardless of what anyone tells you.

 

[chanwmr]

Thanks all! I'll be seeing her in about a week. I have a scanner so I'll get the code(s) then report back. I'll try to take it in for more opinions too.

 

[CWBenjamin]

If it's those P0420/P0430 codes you must have operating O2 sensors for those codes to set.

You can not fix those 2 codes with new O2 sensors and you can't clean cat's regardless of what anyone tells you.

If it's those P0420/P0430 codes you must have operating O2 sensors for those codes to set.

You can not fix those 2 codes with new O2 sensors and you can't clean cat's regardless of what anyone tells you.

I've seen you post this on a couple threads about P0420 code... I am wondering if you can explain your knowledge of this?
If you search the internet, there are hundreds of trustworthy mechanic pages that all say a faulty rear 02 sensor could cause a P0420 code to be stored.
So can you explain why this would be such common knowledge if it was incorrect? I have read many forums about this code and you're the only person I have seen make this claim, so if you are correct I would like to be able to share your information. Thanks

 

[blanchae]

Old thread but it is pretty rare for both codes P0420 and P0430 to show up together. There are two cats and each cat has 2 O2 sensors: an upstream and a downstream sensor. P0420 is one side and P0430 is the other. It's highly unlikely that both cats or a pair of O2 sensors fail at the same time.

In my experience, it is a wiring harness/connector problem. I had a 1999 Mercury Cougar that maybe once a year, when it was really wet out (rainy weather), it would throw both O2 codes then the wiring harness would dry out, I would clear the code and it would be good until it heavily rained again. Also happened if I pressure washed the engine compartment. On our 2006 Jeep Liberty, we had a power steering pressure hose leak and the engine compartment was coated with oil. I pressure washed it at the car wash and suddenly both the P0420/P0430 codes showed up the next day. I would suggest cleaning the O2 connectors with contact cleaner as an inexpensive start. On another thread, they mentioned that a leaking gas cap could cause both codes also. Clean the gas cap O ring just in case (costs nothing to do).