stumped

My 97 Cavalier started misfiring.. we put it on the machine.,and it reads error code 301-Cylinder one misfiring. We replaced the spark plugs,fuel filter,and new wires and its still misfiring..Anyone got any suggestions???

You need to verify that you have spark and fuel if you are getting a cylinder misfire code. Unfortunately you have not done that by merely replacing parts. You'll need to get a NOID light that will fit your GM car, which you can get on ebay or at an autoparts store. With the engine idling, remove the connector on the #1 injector and plug the NOID light into the connector. If the computer is properly actuating the injector, the NOID light will blink rapidly. If not, the light will not blink at all. If the light does not blink, then you need to check all wiring from the injector connector back to the computer for continuity, including the injector fuse. There is the possibility that the fuel injector is clogged. Do you run the tank down to E often? The NOID light will blink rapidly, but since it is clogged, no fuel will get to the cylinder.

If the NOID light blinks rapidly, then you need to verify that you are getting spark at that cylinder. Get an in-line spark tester such as this (http://www.thetoolwarehouse.net/shop/TA-23900.html) one. Connect it between the plug wire and the spark plug on #1 cylinder and crank the engine. If the light flashes in the tester, then you are getting spark. I don't suspect that you are having a problem with spark, as you would be getting a misfire in #4 cylinder as well due to the design of your ignition system.

Chances are either an injector is clogged, the wiring is bad, or even the computer is faulty. Perform the tests and let us know.