#4 cylinder missfire

i have a 99 tacoma reg cab 4x4 with a 2.7. i have very bad skip on cylinder 4. no power and converter gets red sometimes and then clears up. ive replaced wires plugs and #4 injector. pulled converter and started engine still missfires. it tries to clear up but then starts missing again. compression and timing are good, flushed fuel system and put in new fuel. also preformed top end cleaner service. after that was done i have a brown sticky oil looking substance leaking at front converter flange. any ideas im ready to take a match a hold of it.

 

99s have 2 coilpacks, one is like 1/3 other is 2/4. swap the 1/3 for the 2/4 and see if the misfire moves, if so, replace the bad coilpack. also check the MAF to make sure its within voltage spec, and or try cleaning it