ummm...what does tis mean?? also the 2 plugs that were bad, the plug wires or whatever you'd call them were dirty. Does that mean they need to be replaced??
celica has direct ignition, there are no plug wires like on a distributor powered car, (the celica also does not have a distributor hence-direct ignition)
the parts that sit over the spark plugs are actually called coil packs, they are individual coils, that are used to generate a spark to the spark plug.
the nice thing is that you can electronically advance or retard the timing, unlike distributor powered cars where you can only set it to advance or retard by a certain degree.
mis shift is a common term for blowing the engine. Its most commonly done by accelerating lets say in 3rd gear and the driver attemping to shift fast into 4th gear at 3rd gears redline, but the driver instead shifts to 2nd gear thus reving the engine up to superhuman speeds, causeing piston to valve contact.
since this engine is an interferance motor (meaning the valves will contact the piston if out of time) bent valves will result and or trashed pistons/head/motor.
when you get missfire in all 4 cyliders after a miss shfit thats the best indicator that you have bent valves because the valves wont seat properly and you wont have proper combustion, thus mis fire.
however it sounds like the 2 fouled plugs were the culprit, but if your cell turns back on and its misfire again, a mis shift could be the culprit.