I noticed some stumbling of the engine when maintaining speed up hill or accelerating in a high gear. One day the check engine light started flashing and then stayed on. The day I was to take it into the shop to get the codes checked checked, the light went off and stayed off for about a week but the engine still stumbled under the sames conditions. About two weeks later the light came back on and I got it into the shop to check the codes and it came back as an engine misfire. They sugested I change the plugs. As I had just changed the plugs 6000 miles earlier I thought this was a bit strange, but the service manager told me that if I had used Bosch platinum plugs that was most likely the root of the problem. So I changed the plugs again using the NGK plugs recommended in the owner's manual.
The engine purred likem a kitten
For about a hundred miles and it started all over again. I'm now thinking that it could be either the Crank Position Sensor, Throttle Position Sensor the Coil Pack. God help me if it's the control module.
Gas mileage is still fine and the problem with the stumbling is intermittent but chronic. It has yet to stall during one of these episodes.
Am I on the right track with suspecting of the sensors the sensors? Also I am aware that the timing belt is overdue for service. Can those things stretch to a degree that this kind of thing might happen? I remember having an old Dodge Colt with a stripped crank pulley and the engine would stumble in much the same manner.