Hyundai Repair: Car shudders going up hills, hyundai accent 2000, spark plug wires

Question
My Hyundai Accent 2000 shudders and slows way down when going up hills. New spark plugs were put in last week because this happened then, and for about five days was driving normally. Now its back.  Any ideas please?

Answer
The fact that the problem went away with the spark plug replacement (even if only for a short period of time) suggests that its cause is with something that was disturbed during this replacement.  There could be a problem with one of the spark plug wires or a defective spark plug could have been installed.  A defective ignition coil can cause the same symptoms as a defective plug or wire, but this wouldn't typically be disturbed during spark plug replacement.

A transmission or clutch problem can also cause a lack of power under acceleration and up hills.  Key in determining where the problem lies is figuring out whether the lack of power originates in the engine or the transfer of power from the engine to the wheels.  If you're unable to figure this out on your own-- and I don't expect you will be; few laypeople have this ability-- you'll need to have an experienced and qualified mechanic check the vehicle.