• Welcome to the New OffroadSC - We have successfully migrated to our new Non-Profit Servers. Our team has been working hard to make this migration as smooth as possible. If you experience any issues, please let us know via the Housekeeping > Technical Problems Section.

Catalytic Converter question

LBarr2002

LIFETIME
SUPPORTER
#1
My mom's '07 Yukon XL has been having some issues. It had a misfire on the right bank (#6 I think). They changed plugs, wires, and I think intake gasket and got that straightened out. Shortly after it started throwing P0430, catalyst below efficiency bank 2. Our thoughts are the misfire may have ruined the converter?

Bank1
20190925_200939.jpg

Bank2
20190925_200917.jpg

Anybody ever see a converter look like that? What would cause it?

We bought an Evan Fischer REPC960340 replacement cat pipe from carparts.com's ebay store. Dad swapped it out over the weekend and yesterday it threw P420 and P430. So it doesn't like these converters or they're not "doing enough"?

Thoughts?
 

LBarr2002

LIFETIME
SUPPORTER
#3
He swapped downstream sensors side to side before changing the converters and the code stayed on bank 2. The drivers upstream couldn't come out without removing more stuff, so he didnt swap up streams. But, code staying on bank 2 and now codes on both sides rules that out in my mind.
 

LBarr2002

LIFETIME
SUPPORTER
#4
Dad went by a local shop that he knows the owner and mechanic well. They said they've run into this before where the aftermarket converters aren't efficient enough for the computer. They won't install anything but OEM, and said nobody ever pays for OEM. They have a junkyard supplier that with customer approval they'll put OEM junkyard ones on.
 

LBarr2002

LIFETIME
SUPPORTER
#11
Throw an aftermarket cat on it and take it to v8muscle.net in piedmont and have that hting tuned. Turn off DOD while you;re in there.
I knew that would be your answer. I've already talked to Charles and he'll do it, just not 100% sure that's what dad wants to do yet. I filed a return request with ebay to see if he can get any money back on it, so the aftermarket ones may come back off.
 

LBarr2002

LIFETIME
SUPPORTER
#12
Resolution on this.

Ebay granted a return and dad shopped around for another brand that had good results. We ordered a Bosal 079-5218 from Summit. In the meantime, Dad got pneumonia and was pretty much down for a couple weeks. Friday a week ago he finally felt up to tackling changing it again, returned the Evan Fischer and it's fixed.
 
Top