2013 Ford Explorer Limited 3.5L V6 Naturally Aspirated.
Hi Scotty, I wanted to ask if this would be a reason for vacuum leak and/or a catalytic converter codes P0420 / P0430.
I went to replace my spark plugs to see if it would improve idle surge, low fuel mpg and my cat code. I found both sides of my valve covers leaking into the plugs for cylinders 2 and 5.
Since then, I ran some cataclean. The CEL turned off, MPG went back up to 18.3 and the Surge went away. but after about a month, the CEL is back with the Codes. I need to pass inspection by August.
I cleaned the MAF with MAF spray, new plugs and pulled the Bank 2 cat and cleaned with carb/choke cleaner and cataclean. So far, not fixed. I did note..the honeycomb was used but not broken or clogged. I found a crack on the weld the attached the Cat Brace to the Engine Just below the downstream sensor. It appeared to be just the weld and not into the exhaust piping.
My plan now is to ordered new fuel injectors and the valve cover gaskets to update and see if it fixes my cat issue.
Following that it will be new Cats. Any other recommendations? Can the valve cover gasket or air intake gasket cause a P0420? I would expect the computer to tell me different codes, but not sure that is built in.
Thanks for your time.
Carbon build up can also trigger code P0420. Had that happen to my 2014 Jeep Grand Cherokee Lared threw that code up but there were no symptoms of a failing O2 sensor or cat but it did have some power loss. Bought Seafoam Intake Cleaner and after it cleared all the carbon out the check engine light and code P0420 was killed
