I am at 140K, have been fine all year, no problems since last October 2016 post, now suddenly, TP sensor (TPS) again. Have swapped it out. I disconnect ground, remove the 3 wire harness's around the TP sensor, replace it, re connect ground. Car won't start on first try because I think Brain Box is learning new sensor, then on 2nd start, presto. This was 3 weeks ago. Today it did it again. I still had previous sensor. Put it back in and it's RUNS again. I have never thrown any codes like the books says it might. No codes at all. I have cleaned all the connections and checked for loose or frayed wiring. Any ideas?

Manual Says nothing relevant to me:

The throttle position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. The PCM monitors the voltage on the signal line
and calculates throttle position. As the throttle valve angle is changed (accelerator pedal moved), the TP sensor signal also changes. At a closed throttle
position, the output of the TP sensor is low. As the throttle valve opens, the output increases so that at wide open throttle (WOT), the output voltage
should be above 4 Volts.The PCM calculates fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor may cause intermittent bursts of fuel from
an injector and unstable idle because the PCM thinks the throttle is moving. A hard failure in the TP sensor 5-Volts reference or signal circuits will set
either a DTC P0122 or DTC P0123. A hard failure with the TP sensor ground circuit may set DTC P0123 and DTC P0112. Once a DTC is set, the PCM
will use an artificial default value based on engine RPM and mass air flow for the throttle position, and some vehicle performance will return. A high idle
may result when either DTC P0122 or DTC P0123 is set. The PCM can detect intermittent TP sensor faults. DTC P1121 or DTC P1122 will set if an
intermittent high or low circuit failure is being detected. The PCM can also detect a shifted TP sensor. The PCM monitors throttle position and compares
the actual TP sensor reading to a predicted TP value calculated from engine speed. If the PCM detects an out-of-range condition, DTC P0121 will be set.