Throttle Position Sensor help?

Question

99 infiniti g20t, checked engine code, it said Throttle Position Sensor circuit malfunction. changed the sensor, put it on right by a manchanic and won't to get code erases, 30 secs later, light pops on again. same error egine coded. also code reads Throttle Position Sensor circiut malfunction and i did put on a different sensor, any one knows what it could be?
car sometimes turn off when first started
low rms during idle, just a pinch over 500rms when fans turn on
about 1500 with fans off
tried get codes erased, but still pops up
car is 5spd, so when i push in the clutch and car is in gear, rpms go up to or above 2000, is that nomal

Answer 1

Disconnect the Neg (-) cable going to your battery for about 5 minutes.This should erase any existing codes.If this fails.Some newer vehicle codes must be erased by a dealer that has access to your onboard computer.But try disconnecting and replacing the battery cable first.Good Luck

Answer 2

What was the code number?
Are you sure it was for the TPS, and not for the idle control?
Nissan has a known issue with their idle control circuit.
If the issue is indeed the throttle position sensor, gather the wiring diagram, and find all of the shared sensors that get their Vref from the same source, and then check all of the circuitry using proper diagnostic methods.
Check all of the wiring harness for pinches and chafing.
All of this will take some effort and time, and will require a DIGITAL volt meter and ohm meter at a minimum, and a scanner that reads live data would be a wonderful option.

Happy Motoring

Answer 3

Assuming the new sensor was good (once in a while, Murphy *really* kicks in and the replacement part itself is NG), you'll need to start looking for a problem in the wiring and any connectors between the sensor and the computer. All of your symptoms indicate that the computer is not successfully reading the TPS. There's a remote chance that the A to D conversion in the computer itself is failing, but you don't really want to go THERE until you've eliminated the inexpensive possibilties!