Club Car MCOR Throttle Models Explained
Club Cars use an MCOR throttle device. This translates your foot movement at the pedal into electric impulse that the motor controller reads. MCOR stands for "Motor Controller Output Regulator".
There are four different MCOR models from different years and cars:
MCOR1 - This was used on all DS & Carryall cars from 2000.5 until 2011-2012. It looks very similar to an MCOR2, but the input shaft is star splined and they mount differently. It is no longer available. A conversion kit upgrade to MCOR 3 or 4 is required to replace it (AM293101). This kit is for a DS and will not fit Precedent. 
MCOR2 - The model for Precedent cars. This looks very similar to the MCOR1, but it has a different input shaft and mounting. MCOR2 are still being made and available. If you have Pedal Group 1 (see notes below), you have no choice but to replace it with an MCOR2, unless you change out your entire pedal group. If you have Pedal Group 2, you can get a conversion kit (AM293001) to an MCOR3 or MCOR4. If you have a 2009 Precedent read the TPS sensor note below.
MCOR3 - This looks identical to the MCOR4 that replaced the MCOR3 because of problems. But reports are that the MCOR4 is not necessarily any more reliable. And most MCOR3 models function perfectly. This will not work on a Precedent with Pedal Group 1 (see not below).
MCOR4 - The current model for some DS & Precedent cars. A conversion kit may be necessary if you don't currently have an MCOR3 or MCOR4 installed. Read above to see if a conversion kit will fit your vehicle. This will not work on a Precedent with Pedal Group 1 (see not below).
V-Glide or Potentiometer
Earlier DS cars had either a V-Glide or Potentiometer throttle. You can get a conversion kit (AM293201) to MCOR4.
Precedent Pedal Group 1 & 2
Pedal group 1 uses MCOR2 only. There is no conversion kit to MCOR3 or MCOR4.
Pedal Group 2 came out around 2008 and can use MCOR2 or MCOR3 or MCOR4 with a conversion kit (AM293001).
2009 Precedent TPS Sensor
Year 2009 Precedent cars changed to a TPS sensor (Throttle Position Sensor) instead of the MCOR2. It did not work and was warranty replaced to MCOR2. If your vehicle been converted to MCOR2 it will have the adapter in the picture. In IQ vehicles this is just a pin converter. In Excel models it has resistors inside. 