Cat system efficiency threshold codes

[flanative3]

Last week I had both p0420 and p0430 come up. I replaced spark plugs this past weekend since I had planned on doing so anyway and cleaned throttle body while I had the air intake apart, coils looked to still be in good condition but replaced the boots anyway since again I already had them out, engine air filter also looked good other than a couple of bugs and a few other bits of debris but not too bad. Codes didn’t come back until today. I was going about 30mph and the car had a hard jolt that felt like a sudden loss of power and immediately started driving fine again, codes came back. There was a little bit of an egg/exhaust smell that went away after doing the spark plugs. Any ideas? 2013 XLT 3.5L NA AWD

 

[peterk9]

Here is a thread on that. Maybe it will help.

P0420 and P0430 Codes

I have purchased a 2015 Explorer Limited 3.5L V6 that did not pass smog check. Batter was replaced just before i bought it so figured the vehicle had not made its way through the drive cycle. Engine light then came on while driving around during drive cycle. I have reset the light with an...

www.explorerforum.com

Here is another one that may or may not be helpful. Fix P0420 P0430 for only 10$

Peter