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Q: ongoing p0302 on 1999 Chevrolet Malibu

I've replaced plugs , wires , intake manifold gasket , coil pack , switched injectors around , replaced catalytic converter , and still get an intermittent number 2 cylinder misfire . any ideas ??
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Could you tell us which engine it has? Perhaps the VIN#?
First I'd check all TSB to see if there is any about misfire(s).
Check the harmonic balancer.
Smoke test the intake manifold while cold and hot to make sure there is no leak - especially around #2 cyl.
Check the electrical connectors to #2 fuel injector and ignition coil.
Scope test the secondary ignition to see if misfire really occurs, and not just the ECM thinks it does, eliminating ECM problem. Perhaps needs a known good ECM to do so.
Than I'd check the compression in all cylinders and see the reading @ #2 are similar to the others. Next step wold be a leak down test to see if #2 cyl. is sealed correctly.
From here comes the major operation: I'd check the #2 cyl. push rods, than cam shaft lobes.


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