I'm currently hauling a 5-6k trailer across country. About 2-3 hours into the trip my "service engine soon" light came on. I got a code reader from Walmart and I am getting 3 codes; P0301(cyl #1 misfire), P0301(#2 misfire), and P0171(system lean bank #1). I've cleared the codes multiple times, and they keep coming back within an hour of being on the road.

The van idles rough and is pretty sluggish on the highway.

It's a 1999 E150 econoline with the 5.4.

Any suggestions on where to start to diagnose this problem would be awesome.

Thanks

 

Sorta having same problem. 303, 307, and system lean bank #2

How did you make out?

I hope you fixed by now!!!