This is a 1997 F-150 Lariat, 2wd, 4.6L, 8 cylinder, automatic, 3rd door, short box.

Here's the recent history-

I had terrible misfiring 6 months ago, I replaced the plugs and wires but still had a problem. I brought it to the Ford Dealer next who diagnosed an intake manifold gasket leak, so they replaced that. It ran fine for a few days, but then started bucking and kicking again and bogging down. I thought I had a plugged cat because I heard that raw fuel dumping in because of the gasket/fouling issue can kill a cat ( I only still had the right side cat anyway, left had been removed before). Truck sat for the winter.

So I removed the right side cat this spring, problem still not fixed. CEL said #4 cyliinder misfire. So I changed the coil packs for both sides. It seemed to be slightly better, but the next time I drove it til it warmed up, it started missing again. I changed the #4 plug (hardest plug in the world to change), but now today after warming up, the misfiring continued. CEL codes now say 2, 4, and 8 misfires, and of course a code for the emissions.

Any ideas?

Thank you.

 

A couple additional symptoms-

When at highway speeds, the missing is like a pulsing surge, bog, surge, bog kinda thing. At slower speeds (25-50) the missing is much worse the higher the gear I'm in. Like in 3rd or OD at about 45 mph the motor feels like its gonna jump out the hood. Also, I often smell fuel when I'm getting out of the truck.

Thanks

 

How do the plug wires look?