Seeking recommendations for replacing catalytic converters on a 2007 LS460L with 136,000 miles. Previous error codes include PO430, PO420, PO137, and PO328. Reliable and cost-effective sources for the parts and labor are appreciated. Would purchasing from a junkyard or discount parts store be a sensible option? How much can I expect to pay for this replacement?

 

One cat failing i could beleive. Both failing at the same time can happen but usually if both codes are on something upstream is the issue. Something that affects both banks. More so if both codes came on at about the same time.

Good luck.

 

I’m so confused right now I’ve had a PO420 and a PO430 on at the same time unfortunately when I replaced the battery last week everything cleared but now just PO430 is on. Thanks for the input

 

You probably have a small exhaust leak somewhere in your intermediate pipe before or at the o2 sensor/s

 

Check for exhaust leak
Check to make sure the actual sensors are working correctly
Make sure you aren't just burning so much oil you killed the sensors or cats

 

Same problem. I kept replacing the gaskets between the cats and exhaust. Advance auto kept selling me a thin approx one eight inch thick crush gaskets. They lasted for a year and had the problem over and over again. I researched and found the proper gasket is Fel Pro 61460. They are much thicker and tapered approx three eight inch. No more codes shown for years.

 

Thank you for your help

 

I appreciate your help

 

Thanks so much