I have a 97 cobra stock motor and it has a miss or is breaking up and it didn't occur until I got into it a few times within a 2 day period. I have new wires and coil packs and I found 1 plug that was bad cause I had a cylinder 5 misfire code. I did a compression test and all cylinders were in spec (cylinder 6 was 18 psi lower then the rest but still in spec). And I've noticed that when I start the car up it has no miss and if I give it gas it doesn't do it but when I start driving it does it but not bad unless I get on it pretty hard. I've since replaced all the spark plugs and no change. What could cause this bad injectors?