These damn COP's!
 

I had the rough running/bucking problem with the engine a few months back. It was also throwing the "lean on banks 1 and 2" code. I replaced the injectors, plugs, and COP's (the ones off of E-Bay). This took care of the code problem and the truck ran much better. A couple weeks back it rained pretty good. I guess water got thrown up into the engine because it started running rough/bucking again right after. It was a pretty good rain, but nothing horrendous.

Why do the COP's seem so fragile when it comes to rain? I really don't want to have to mess with them every time it rains. Is there something that I should be doing to protect them better? It started throwing the code again so i'll get that checked out as well. If there are only 1 or a few that are bad, is there any way to diagnose which ones they are, whether installed or taken off.

Has anybody been experiencing this type of repeated problem? Thanks for any suggestions.

The boots need to be properly greased. The inside of them need dielectric grease, being careful not to get grease on the spring contact. You should also grease the outside at the top to help seal the area between the boot and well.

Without a misfire code, the only way to test them is by substitution, one at a time. I hope you kept the old ones.