I have a 2000 Ford Ranger 4.0 L 4x4. My check engine light has been on for several weeks now. I hooked up a scanner up to it and the reading said P0153, generic sensor error. I was told one of the problems could be a vacuum leak, however with the engine running, I can't hear for a leak. How else can I check to see if a leaking intake manifold gasket could be causing my check engine light?