2000 camry shakes

Can somebody please help me, ive got problem with my 2000 camry manual transmission, recently. when i start and shift to 1st gear and the car starts to move i can hear the engine and the tube(connected to the muffler) underneath the car shake. even if i step on the gas properly. but after 20 minutes of driving the car starts smoothly. ive recently changed the sparkplug and change oil just to check the problem, but it is still there. does it have anything to do with the amount of current running?

I guess some clarification would help. What do you mean by “i can hear the engine and the tube(connected to the muffler) underneath the car shake” does it mean you can hear a rattle noise from the bottom of the car, & what tube you’re talking about exhaust tip at the very end? Also “but after 20 minutes of driving the car starts smoothly” meant that on the cold engine it’s rough idle and then you hear the noise while attempting to drive in the first gear, what about 2nd and 3rd?

yes the engine shakes. and also i can hear a rattle underneath so i guess its the exhaust tip and its tubing maybe?
actually the idle is smooth.but on first gear going to motion i experience the shake. but moves smoothly by 2nd, 3rd, 4th 5th gear.

R U in the salt belt, corrosion prone area?

I'd take it to the exhaust shop and have them check the heat shield/shields (i think your car have multiple) If that's what it is, you may have to replace the portion of the pipes that has a loose shield,
or in some cases ol trick with a piece of wire properly tighten around the shield, helps.

Thank you, i tried to do it with wires to tighten it and it worked.

Glad it helped, next time it will probably require a replacement....