I also suggest cleaning the injector bores very well, I did mine, although they say no lube on the seals, I did put a "Tiny" bit of the 0W20 on them just to barely wet them. I didn't have any issues, just make sure you clean the bores, I used intake cleaner, and a nylon bore brush, then flushed with Brake Cleaner and dry. If for some reason one or more of the Teflon seals are damaged on new injectors (it happened to me) be sure to watch videos on how to install them, very critical!!