I have a 91 SE with 190K miles on it. Recently it started running on 4 cylinders (actually it still performs pretty well for 2/3rds of the engine). It does it at idle, accelerating and while cruising. I removed the #1 and #6 spark plug wires and found the engine ran the same. I listened to each injector and found the #1 to be quieter than the others and the #6 injector makes almost no sound (I was listening for the clicking sound). There is power at the injector (I checked it with a voltmeter), but I don't have a scope to check if it's pulsing. Before I replace the injectors (a fairly big job and the injectors are pricy) I'm wondering if there could be another cause for this. Would the ecu shut down 2 cylinders or is there a known harness problem or injector problem? -Thanks