umm, help

1991 ford ranger 2 wheel drive, i think 2.3 liter: i was passing a old lady who was going about 55 in a 60 mph lane, i passed her doign about 65-70, then ten minutes later i noticed the engine was laging a little, then it sounded like one of the pistons was gone, or the spark plug was bad, can anyone tell me what went wrong or if this has happend

How hard did you push that poor 2.3L? Does it lope like a dragster when it's just idleing? It's probably missing, the reason is hard to say though. It has 8 spark plugs doesn't it? The piston missing is not likely, it has to go somewhere. If it broke, you would have heard a knocking then a TING! Check your plugs. You engine will tell you a lot about how it's running by how the spark plugs appear. If they all look ok, then I would isolate which cylinder is missing. From there it will be easier to figure out what's going on. No check engine light?

yea, i cleaned four plugs today, i didnt want to remoe alot of stuff to get to the opther four, and they were just didrtya nd it runs fine now