Sorry for asking about COP problems, but Ive searched and cant find anything like this. I have a 2000 F150 5.4, I changed COPs with Autozone brand, and plugs with Motorcraft all in the past year. However I am always getting a P035x code about every 3 weeks on different cylinders after ive cleared codes. Recently the temp has been 9 degrees, on the first morning my truck almost died then had codes P0352, P0357, P0356 show up and drove to work with a minor miss. I cleared these codes and next morning started truck it died and started back with codes P0354, P0355, P0358 ran rough for a minute then drove again with slight miss. My question is could all these COPs go bad in 2 mornings or do I have a deeper problem? PS I used dielectric grease in COPs and have good connections, and there is no TSB reflash for my PCM.What now? Could someone please help!!! Again sorry but having no luck in search! Also my truck has intervals of a few weeks where it runs fine, may have only slight miss but no codes.