My 2000 Cherokee Sport with 88k and 4.0 started kicking out codes about a week ago. My first code was P0306 cylinder 6 misfire detected. I changed the plugs which took care of the very rough idle and stalling, now it just won't run smooth. It kicks out codes then they go away, I get P0340 (Camshaft position sensor A bank 1 circuit malfunctuion) and P1391 (manufacturer control ingnition system or misfire) Please can anyone steer me in the right direction to get my motor to run smooth??? The camshaft sensor is $68.00 from the dealership and looks easy to swap out but I don't want to spend money if I don't need to. I also put in a bottle of fuel injector cleaner and I cleaned my TB and checked for dirty air filter. Thanks for any help!