The wife's 1998 Camry was running fine until the other day it started sputtering. It has 270 k miles on it and the plugs, wires, and timing belt were all changed last year. It's been smelling recently like it has been burning oil so I pulled the plugs out and put new ones in. It still sputtered so I pulled one plug wire off at a time while it was idleing and the #4 plug had no affect on the idle. My question is can only one side of a coil go bad? I ordered the front coil pack today and I'm assuming it has to be the issue since all the other plugs are working. I do have the thought of the cam position sensor. Anyone have an idea on this? It can get very expensive just buying a few parts and being wrong. I've checked coil packs on a buick by pulling the cables off and looking for spark between the posts. Anyone know if this can be done on a Camry with no harm? Thanks.

Last night I pulled the #4 plug wire slightly from the coil and had the son-in-law turn the car over in the dark. There was plenty of fire, so I plugged the wire back in and had him start the car. There was spark jumping between the two wires on that coil. Today I will buy new plug wires and see if that fixes it. It is disapointing that the new wires I put on it last year would be bad already. They are half the price of a coil though.

They call that the "lost spark system" meaning that to simplify things (only explanation I have ever received) they fire the plug in the cylinder on the compression stroke and also the one on the exhaust stroke, which does not, of course, do anything except wear that plug, but plugs last a long time these days. If the coil pack were bad you would lose two cylinders, so suspect the wire. OEM wires last a long time, I have found NGK makes the best, but not the least expensive, replacements. Even the " on commission" dealer service writers don't dare frown on NGK wires. after all the OEM plugs are often NGK. BTW single cyklinder lawn mower type engines with the spark generator on the flywheel are also "lost spark". You could swap wires from that coil pack and see if the other cylinder now has the symptom. (you gotta swap the at the plug end, though)