Like i need more costs..lol. I am getting another error code. P0420. Anyone experienced the same?

 

P0420=catalyst system effeciency below threshold, How many miles? GM upped the milage warranty on the cat' convertors to I believe 140,000mi. Mine was replaced at 83,000mi on my '01. Then they changed the warranty a few months later and wrote me a check for the full cost. Over $300.
Is your performance down? Shifting funny? No top end? It's your catalytic convertor. Make sure your mufflers aren't clogged from it, either.

http://www.cardomain.com/ride/2319272

 

I dont think I am under warranty. I will have to call. It is 03 and i believe it is only a 3 year. Does anyone know differently on 03 warranties? Performance doesnt seem to be down. A little rough on idle ( but perhaps i need to clean the injectors?) and start-up sometimes squeels for just a second. Slight "Putt" sound from the exhaust. Otherwise when she is openend up she still moves. I tried to clear the error thinking it was temp but even after clearing it, 1-3 days later it is back on.

 

Oh and it has around 81,000 KM. not sure what the conversion to miles would be. Is the warranty on the Cat separate from the rest of the car warranty?

 

Yes, the warranty is different than the basic drivetrain warranty. It is good for 10 years or 120,000 miles, according to my info from the search engine here.

http://www.cardomain.com/ride/2319272

 

I'm having second thoughts about what's wrong. If there is no loss in performance, milage, or any shifting problems, then the culprit could be the downline O2 sensor failing, or a bad connection or corroded wiring causing a bad reading, if the ohms coming thru aren't correct. I'm leaning this way more today.
Besides, a bad cat' doesn't usually throw an error code. That's why they can be hard to diagnose. Check the downline O2 sensor.