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Q: My 2007 Grand Caravan hard detonation problem

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My car lacks power, misfires,, cannot drive over 40 mph because it starts to shake. So far replaced the ignition coil, sparks plugs, spark plug wires, crank shaft sensor and TPS. OBD II scanner detected cylinder misfire 1 and 3 (back) and 4 (front). Spark plug from 4th cylinder was burned. Put Cataclean and B-12 Chemtool on the tank. Runs smooth until you hit the accelerator.

My car has 180000 miles.
My car has an automatic transmission.

A: As you know, a misfire can be caused by man...

As you know, a misfire can be caused by many different reasons such as bad spark plugs, spark plug wires, faulty fuel injectors, lack of voltage to fuel injectors, incorrect fuel pressure, an air intake leak and many other possibilities.

The fact that spark plug #4 was burnt suggests that you may have a lean fuel condition which is usually a result of an intake air leak or potentially a bad fuel injector not supplying enough fuel to that cylinder causing it to lean out and burn the plug. This would also explain the shaking and lack of power due to the motor starving for fuel. I would recommend having an expert from YourMechanic come to your location to diagnose the misfiring problem so that this can be corrected.

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