I have a 2000 Jeep Grand  Cherokee 6cyl with the following  problems...
It is hard to start - always
Rough idle - always
Knocking or popping sound from engine - intermediate
Lacks power on acceleration, popping sound - intermediate
Engine light comes on and goes off
Recently changed the plugs, dont know what else to check.
				
			It is hard to start - always
Rough idle - always
Knocking or popping sound from engine - intermediate
Lacks power on acceleration, popping sound - intermediate
Engine light comes on and goes off
Recently changed the plugs, dont know what else to check.