I have a 93 Mustang with a 2.3L 4 cylinder automatic and Im having some issues. My tachometer started acting up a few days ago, it would start out fine then the needle would drop to a lower rpm than the engine was doing, then it would bounce back, no problem. Then today the needle dropped and the check engine light came on, once the needle went back to normal the light went out. It did this a few more times when I came home. Has this happened to anyone else and can anyone advise me on whats going on and how to fix it? Any help is appreciated, thanks.