Either way its not a bad thing to look into if they slide around on the nipples with ease and you can pull them off and see that they are gunked up pull them and replace them. With tools on the bench it wont take longer than an hour. The hardest part is getting to some of the parts of the system that are tucked up under the steering column. But checking to see takes no more than five minutes... And thats just the time it take to walk to the garage and pull a fuel line off.