Hi Scotty,
I have a 1996 Toyota celica 1.8 7afe and these are the codes I have. P0300, P0301 cylinder 1 misfire, P0302 cylinder 2 misfire and P0304 cylinder 4 misfire.
Two years ago the just died and didn’t start for months. I changed the fuel pump, Engine Crankshaft Position Sensor, Ignition control module, spark plugs, wire and nothing.
Took it to a shop and they said it was the computer. We changed the computer the car turned on and ran but the car started misfiring a few months after.
Ok my friend, check the battery, not just the voltage but the cold cranking amperage.
second, check for vacuum leaks, if it’s sucking air that could be it.
spray some carb cleaner around the intake and any vacuum lines per se.
if you hear a change in idle you just found your misfire and a repair will be in order.
