it would take alot of rain to do that , but i have seen trucks come in during a snow storm , and the box be quite full of snow , and turn the gauge minder on , as far as rain i think it would have to be a very heavy rain and i think you would have to be traveling on the highway to get that much water to do engine damageSo ther's a possibility of turbo or engine damage in heavy rain ? sound a bit scary.Just how much does it improve performance ?
even with a K&N filter, or just the stock unit ?If you plan on keeping that truck, you really need to atleast do a do it yourself tymar air filter. the stock box and drop in are very well known for letting dirt by, and that will "dust" your turbo and is not good for the engine either.