2002 Elantra 1 & 4 cylinder backfire

I have a 02 elantra 2.0L and have been experiencing some issues with it. The check engine light came on and I took it to an autozone. they hooked up the tester and they told me that the #1 and #4 cylinders are backfiring and to change the spark plugs and wires. I did so and took it back up there when the problem still existed. they told me the exact same thing again. the car shutters when it idles and it idles high. It also seems like the clutch is slipping when I drive it. I am so far clueless and was wondering if anybody has any input for me. PLEASE HELP!!!!!!

Chill out a second...

First of all, the Autozone guy said "the #1 and #4 cylinders are backfiring and to change the spark plugs and wires"??? Bad plugs or wires won't go bad in pairs like that.

The Autozone guy is not supposed to diagnose your problem, only read the codes. Diagnosing codes is the job of a technician, or a forum junky. Did you note the codes? Did he write them down for you? If not, go back there and get another scan and write down the codes.

We need the codes to diagnose the problem, but I suspect the coil pack is bad. Cylinders 1 and 4 are on one circuit, and 2 and 3 are on the other. Probably the codes were P0301 and P0304.

Don't let the Autozone guy diagnose the problem anymore, just get the codes.

I verified that cylinders 1 and 4 are one side of the coil pack, and 2 and 3 are on the other. Get the codes anyway, I don't feel comfortable about the diagnosis w/o the codes.