Had my car diagnosed by a tranny shop
 

My only code is p0707 apprently and its external.I need to find my transmission range sensor circuit so i can hopfully replace it by myself without getting charged an arm and a leg.Any info helps..Thanks :)

It's not hard to find, it sits on top of the trans:

ELANTRA(RD) >2000 > G 2.0 DOHC > Transaxle/Transmission > Automatic Transaxle System > TRANSAXLE RANGE SWITCH ADJUSTMENT
TRANSAXLE RANGE SWITCH ADJUSTMENT
1.
Place the selector lever in the "N" (Neutral) position.
2.
Loosen the manual control lever lock nut to separate the cable and lever.

[See large image...]
3.
Place the manual control lever in the "N" (Neutral) position.
4.
Turn the transaxle range switch body until the 12 mm (.47 in.) wide end of the manual control lever aligns with the switch body flange [12 mm (0.472 in.) wide portion].
5.
Tighten the attaching bolts (2 pcs.) to the specified torque.
When setting up the switch body, be careful O-ring does not drop from the switch body. Tighten the attaching bolts carefully.

[See large image...]
6.
Make sure that the selector lever is in the "N" (Neutral) position.
7.
Adjust the flange nut so that there is no slack in the control cable and make sure that the selector lever operates smoothly.
8.
Run the vehicle and confirm that the transaxle is set in each range when the selector lever is shifted to each position.

[See large image...]