Okay, I'll summarize it for those of you with a short attention span. '87 4Runner, 22RE, W-56 a/c etc...
After warming up, truck runs very rich, sometimes stalling, always stumbling. Jumping T and E1 gives me 4 flashes, 1.5 second pause, then 11 flashes. The '93 FSM sticky'd here doesn't give me either of those codes. Any suggestions?

Okay, here's the full history. Truck has 265,000 miles, burns no oil. Just replaced headgasket, had head rebuilt, however didn't have the exhaust studs "fixed" during the build.
Just before the headgasket went (or more correctly, during) O2 sensor needed replacement (got code 5 for that repair). Problem seems the same as when O2 sensor died, just really rich, black smoke, heavy fuel smell etc. So, I replaced the second O2 sensor, no change. Then I began to think the exhaust leak at the manifold may be siphoning air into the exhaust giving a lean signal to the computer. Replaced missing bolts, not the gasket and still same problem. Wiring harness was somewhat brittle during installation, but nothing too bad, no broken covers etc. When I replaced headgasket, I removed the whole top end, wiring harness and all. Unplugged at the ECU, and removed through firewall. All plugs that were unplugged were cleaned with contact cleaner. Finally, when I did the headgasket, I didn't do the timing chain as it was recently replaced and on spec as per the FSM. When I did the install, I removed tension on the chain and it may have been able to be out one tooth, though I highly doubt it happened as I was bery careful to ensure all timing marks were perfectly aligned. I'm at a loss, I've always been able to figure her out, this time I'm stumped and quite frankly can't afford a ton of cash for professional troubleshooting. Any insight you can provide would be most appreciated.