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My car started making a weird shake when im taking off from a stop light. It seems to hesitate. Kind of like a pop. At first I thought it was my slave cylinder, not releasing the clutch right away or something of that nature. The slave cylinder has been giving problems. But today I was driving to work and I got on it. It seemed like it was backfiring a little. Then I shifted like into second and it you could actually hear the exhaust change up a bit. Weird because it was still spinning the tires during that time like it normally does. I first noticed the shake when I was in LA. since then I drove it back home a 320 mile trip. Gas mileage was the same. The SES is not on or anything. Its a little weird. I dont think it would be the transmission, it was rebuilt like 10k miles ago. Smooth as butter. Maybe a motor mount or transmission mount?

Ill check my plugs tommrow and install new ones.

Any ideas? HEEELP!!