So to start off I'm not very competent when it comes to car engines. I can install parts(with instructions) but I'm horrible at troubleshooting engine problems. Here's the problem, I bought a 2001 Cherokee classic last spring with an aftermarket air intake. It whistled for about 20 min. of driving until it warmed up and then it was quiet. over the summer the whistle went away but the coldest weather I drove it in was low 60's. now that I'm back in school I have been driving in the low 40's and the whistle is back and louder than ever. Last night I tried to find the whistle and I tinkered with the air intake and one of the vacuum hoses(Everything was put back exactly the same) Just a few hours ago I went for a drive and the whislte was gone but it felt like there was less power and the engine sounded low pitch. Any ideas? Thanks