Ive been chasing a tip in stumble , and low end balk. I can get a timing light and watch the timing jumping up..jerking around. I have a code that says timing hi/low...i think code 24. It happens after motor is warmed up. I have tried everything and today just disconnected cam sensor after engine was running....symptoms went away. I never knew a cam sensor could do this, and also figured it worked or failed totally. now , gotta wonder where to find one.