Advice Again

To the person that asked me what was wrong with my c-converter. I guess I am not quiet sure but when I took it to AZ their test told me my o2 sensor was bad. The upstream one. I had it replaced and had it retested and it was ok but the test read that my c-converter was below effiencey standerdsor something like that. I hope that this is a little more helpful to you. Also the test read I am misfiring on my #5 clinder. I changed the plugs and wires but it still comes up on the test. They told me it could be the coil and they could be right but it appears to look fine. Is there a way to test the coil before I replace it. Thank you for the help.

Swap coil packs around and see if the misfire code goes to one of the cylinders where the coil in question got moved to.

Make sure the old codes are cleared before running it after swapping things around.

Are you loosing any coolant?