I posted on the another thread about the rough idle smoky smelly exhaust and figured it has to be the injectors. I went to remove them the number one injector required a two foot extension to bust it loose. the number five was already loose and wobbling around the hole. the others weren't even tight. Do injectors rattle loose on their own? Also there was this plastic sleeve around the injectors that disintegrated with the slightest force. Do I need them? they look like something to protect the threads.