My 2005 F250 started missing about a week or so ago, it gets worse when the engine is warm. I took it and got the engine codes today, it has several misfire codes; P0300, P0301, P0303, P0307 and also has a P0174 (fuel system lean bank 2) and a P0430 (Catalyst system efficiency below threshold) I can't afford to start throwing money at it and I really need to get it going ASAP, any advice on a fix or even a starting point would be greatly appreciated.

 

How many miles?

Any service history, like new spark plugs or coils or such?

 

162,000 miles on the truck, I have had it for only a little over a year. I have not replaced anything or had any kind of trouble until now. I don't have any information or service records before I bought the truck.

 

Chances are, the codes are all related. Did you do a google search on them, referencing the year and model truck? Quite often, a simple google search with the codes will point you in a direction of someone who has had, and worked through, a similar issue.

 

A google search will probably just waste time and cause confusion.

You have three separate types of fault codes:

1. Misfires on both banks plus a random (unable to identify) misfire code.
2. Mixture control bank 2.
3. Cat efficiency fault bank 2.

Don't know if you checked for pending codes, but that would be a good thing to also do if you haven't yet done so.

There's a very good chance that the faults on bank 2 are interrelated. Bank 1, not so much.

I'd start with some basics:

1. Check intake system for vacuum leaks, especially in the PCV system. Vacuum leaks can cause "lean" codes, misfires, and resulting skewed fuel trims that can damage a converter or can cause false converter efficiency codes.
2. Reset the PCM and allow the faults to re-occur and get a fresh set of codes. You may have a set of codes that have accumulated over time and are clouding a more specific code or code combination.
3. Check fuel pressure to verify proper fuel supply. The symptoms of a weak fuel supply can mimic those of a vacuum leak.

 

Thank you for the advice, I'll get the codes reset and check these things out as soon as I can and I'll post what I find.