Engine missing

2002 SLE just started intermitent missing. Will run smooth sometimes. Check engine light will come on when it runs bad but will then go off.Changed plugs and fuel filter as it has 97,000 miles. Im currently running injector cleaner in this tank of gas but it seems to have gotten worse. Any ideas, Thanks

Get the code read it may point to a specific cylinder, post back. Did it miss before the plug change?

Yes it was missing before the change, but only intermitently,now it misses all the time.The code indicates #1 cylinder, im guessing injector?

Yes it was missing before the change, but only intermitently,now it misses all the time.The code indicates #1 cylinder, im guessing injector?

Well, you can do an ohm test of the injector to see if it is at fault. Test it cold, and HOT, and compare against the other injectors...

Your code will store even when the light is out.

Another problem could be a bad coil on the cylinder, for diagnostic purposes switch coils with another cylinder, clear the code, when it returns see if the misfire code points to the cylinder that now has the suspect coil.

Going in , any preventive main. we should do while changing the injector?

How do you know the injector is bad?

ohm test, replaced #1 injector, runs great.Thanks for the help.