'97 exped. 5.4 ODB 304

I have replaced a coil pack #2 within the last few monthes and all went ok.Today engine code 304 appeared. Truck sat outside for a few weeks without driving. I read the code (misfire) and assumed it was #4 coil pack. I replaced the pack and the truck takes for ever to start and when it does it is very rough and will not idle (stalls). I removed the injector rail on that side to install coil. I replaced the injector top o-rings. Pressure seems to hold with hand pump. Any ideas what I did?

New codes,1131 and 1151 both indicating lean in each side of exhaust? I checked the fuel cut off, was not tripped?

Scottadam

on the passenger side valve cover is the pcv valve, the hose runs around to the back of the intake manifold, directly below the idle air valve, it's attached by a 90 degree rubber connecter, mine rotted thru, causing a rough idle, check engine light, and a lean burn code for both exhaust banks, try replacing that and reset the comp and see what happens.
hth Rick, Ore