96 Tracker engine light

Hi I have a 96 tracker and the engine light is blinking. I read the code in the computer and it gave me a P0304 which is the number 4 cylinder is misfireing. I have replaced the spark plugs and wires and added a fuel cleaner to the gas. The light comes back on after I have erased the codes. What to do next?

some tracker history, this engine is the 2nd one. Its a 16 valve 1.6 V4.

Thank you for your help.

Mine did that when my timing was off due to a worn out timing pulley on the crankshaft. Maybe try advancing the timing about 10 degrees and see how it runs. Mark it first so you can put it back if necessary. Ed