Throttle Position/Actuator Problems

[Jimlp]

I have a 2006 Limited Expedition getting 2 codes - P2106 & P2135. I have cleared them 3 times and they come back, sometimes in 2 days, sometimes in 2 weeks. P2106 - Throttle Actuator Control TAC System- Forced Limited power. P2135 - ETC Throttle Position Sensor A/B Voltage Correlation.

Is it The TPS or maybe the resistors in the gas petal?

Anybody had experience with these codes? It has about 40,000 miles on it, I have had it about 2 years with no problems.