I had the service engine light on monday with a p1151 and a p0325 (1999 5.4), started it up today and it was still there.I got a couple of miles from work, stopped at the store.When i came out of the store and started my truck the light was gone. Is this a good thing or a bad thing? The truck has been running a little rough the last couple of weeks. I was planning on a tune up this weekend. Can anyone give me a hint on where i should from here?

 

That's a good thing but might be a sign that it's time for some maintenance. If the condition that caused the code disappears, the light will turn off after a few start cycles.

Here's a similar situation - https://www.f150forum.com/f6/how-res...3-f150-404701/