I've got a friend with a 97 F150 we're trying to straighten out. Initially it was running like garbage, so we did some testing and found that the coil for cylinders 4 and 7 wasn't firing. We replaced the coil pack, and still no fire. So, I did some testing, and found the wire from the ECU to the coil pack was broken somewhere, so I ran a jumper wire directly from the ECU to the coil pack. Now it's running a little better, but it's still not right, it shakes a lot and generally runs like crap, with no power. We tested it and it came up with a single code, P0175 Bank 2 too rich. It also had a bunch of tests that hadn't yet completed, because the ECU was unhooked while I was patching the wiring. Any ideas what could cause this?

EDIT: It also has new plugs and plug wires.

 

http://www.obd-codes.com/p0175