please help mechanic 97 2.2 p0300

I got a 97 cavaleir 2.2 p0300 random misfire. I've changed plugs, wires, fuel filter,coil packs, crank sensor and ign module as well as 2 leaky injectors with new ones, and I can still see the spark mising through my spark testers. Could the injectors that I bought be at fault? That wouldn't make the spark intermittent would it. I feel it is a spark problem as I can see the spark cutting out. When I have the testers on there normally they spark fine but you can see that it is intermittent in the cylinders. I am looking for what if anything would be causing this code 300. PCM?? I can't think of anything else to try. Please help this mechanic. Any common problems that anyone knows would be greatly appreciated. I also changed

Bad ground somewhere.

Any experience in mabey a common place the bad ground is on a lot of these?
I assume you mean a bad ground in the ignition system right? Or I suppose it could be anywhere. The battery conections are good and I will check the ground at the mod. Any other suggestions would be great!

Could be anywhere, or even an pinched wire. You've replaced everything i could possible think of to cause a misfire except maybe a bad PCM...

this will sound weird, but unplug the injectors one at a time, if the car starts running better, then start with that cylinder. basically, swap injectors and spark plugs into that cylinder, and if still running badly, then i would lean to broken wire, or bad pcm. at the end pf your post it says "I also changed" and stops....what else did you change? was it a timing chain perhaps? if so was old chain broken? if so i have seen bent valves due to chain breaking on the 2.2's.

im not sure on that car but i know on some cars the crank sensor controls fuel timing and a cam sensor controls the spark timing, it could be a possibility. maybe the coil pack or the distributor cap and rotor which ever one you might have

im sorry u mentioned u change the coil pack

im sorry u mentioned u change the coil pack i had to get 3 different sets of coil packs (brand new) beofre they worked so try that again take them back they should be under warrenty yet and the fuel injector trick thing thats how we solved our bad injector we also since doing all that our will not run on NO GAS STATIONS 87 octane wont stay running with it,we went 89/ethanol mix and it runs like new again dont ask me why i do not know that one for we have had this car since 31298 miles and it has over 132xxx on it and coil packs plugs,wires,oil changes and tires is the only thing we have done to it just putting our 2nd set of tires on this weekend if they get here in time............ gotta love Falken tires