I am doing plugs and wires because I think I have a bad wire and my spark plugs are probably bad,and I thought I might pick up an opti from old Cromer, but not if I dont need one I guess. Will a failing opti always show a code? Could I go wrong with putting in a new one?

Thanks

 

No. That about sums it up pretty well.

 

How many miles on the opti?

If you have the bucks to spend to replace a possibly good opti then do it. I didn't read any thing in your post indicating that the opti is bad. If it has alot of miles on it then it might be resaonable to replace it since it is a wear item and they all eventually go bad over time.

However, I've replaced my opti once because I guessed that it was a problem. It wasn't the problem as I later determined. Now I have a perfectly good opti with 7k miles sitting in a box in the garage.

 

90k on the opti. It is also missing a little plastic piece on the bottom that connects to some line. I just superglued the line back up. That was a pain.

I have one dead cylinder and I would hate to do plugs and wires to find out it was the opti.

 

The Opti will only set codes for problems with the optical sensor module, and wiring thereto... DTC 36 for loss of high resolution pulse, DTC 16 for loss of low resolution pulse. There are no codes specific to the Opti that are set for problems with the high voltage section (cap/rotor). You may get a DTC 42, but it isn't guaranteed, and DTC 42 can be caused by several ignition system components including the coil and the ICM.

 

At 90k it lived a good life. I'd change it.