My number 7 cylinder is mis-firing. i went ahead and changed all my plugs and even the plug wires. but i am still getting misfire. what else could cause this? do you think i need a new coil? if so then how much are they?

 

i would swap coils first. and check those injectors as well.

 

check compression.

 

I hear number 7 isn't a good one to have mis fires on. It usually doesn't turn out to well.