I have a 2001 that runs rough between 1200 and 2000 rpm. Changed EGR valve and plugs and wires. Still have the problem. Codes I am getting are P040, P0171, P0174, P0305. Any help would be appreciated. Thanks

 

Engine? If it is a 4.6, you will need to remove the throttle body and clean out all the passages and also replace the flow sensor.

 

This is in the V-6 forum, Roadie.

P040 is not a valid code, I think you made a typo.

You have both banks running lean. That's usually a vacuum leak, but it can be unmetered air entering anywhere after the MAF sensor. Check the intake tube from the air filter to the throttle body for any holes or leaks. It could be intake gaskets. Can also be caused by not enough fuel, I'd change the fuel filter and test the fuel pressure. You also still have a miss on #5, this could be a bad injector or low compression if the plug and wire are okay and the coil pack isn't cracked.