Hi. I have an 04 f150 heritage with a 4.2l v6 with a check engine light coming back with a bank 1 and 2 running lean. I've changed the MAF, o2 sensors, air temp sensor, fuel filter, pcv valve assembly, air filter. And I can't think of anything else to make these codes go away. Any advice or ideas what it may be?

 

injector's/plugs ??

 

Look for a vacuum leak.

 

Plugs aren't that old. But I'll give them a once over. I wonder if it would be better to clean them or replace them. And supposedly the dealership looked for a leak but nothing came back. I'll look into that again.