<<which is better to try - cap side or engine side? excuse the ignorance.>> I generally do the engine side. I loosen all the wires from the plugs first and put them back in place gently. Then start the car and remove them one at a time with a pair of insulated pliers. Later. --ml BTW: Q: Why do chicken coops have two doors? A: Because if it had four doors it would be a chicken sedan.