The toyota has recently been running kind of weird lately. When put into drive and stopped at a red light, the car shakes a little and the idle is around 500-700 rpm. Then when I drive it and start to go over 40 mph, it starts to shake again. The shake isn't a normal old car shake either. It shakes kind of vigorously as if the cars having a hard time breathing or as if something's loose. Can't really tell where it's coming from but seems as if it's either the drivetrain or bad spark plugs to me. Please give me your opinions because I'd love to try to fix this by myself with the help of my mechanic buddy. Thanks.

Hm, I don't have any experience with the make and model of your car, but it could be a broken motor mount or that the engine is misfiring like you thought. While you're checking the plugs, you might check the vacuum lines too.

Does it shake like crazy when the air conditioner's on? If so, it might be the idle control motor. My friend had that problem once and replaced the motor, which solved the problem.

There's always the option of getting your tires re-aligned and rotated, which you've probably already thought of. Also, is there a lot of mileage on your car? Might be time to change the timing belt. I swear to God, there was no pun intended, because that would've been really cheesy.

Best of luck on fixing your car!

replace the oil and the filter (roughly $40)and the transmission fluid if its automatic