Watch a teardown or throttle body removal video first to get comfortable with the process, then use these notes at the bench.
- Remove the rubber intake hose connecting the airbox to the throttle body.
- Unplug the throttle body connector.
- Undo the four 5mm Allen key screws incrementally in a cross pattern.
- Move the throttle body to a comfortable work surface.
- Cut through the silicone holding the aluminium cap to the bottom of the throttle body.
- Carefully pry up the aluminium plate, working around the perimeter.
- Dig out the green potting compound around the three TPS wires and pins.
- Split the TPS pins from the throttle body pins. They are spot-welded and will not desolder cleanly.
- Remove the four screws holding the TPS to the throttle body.
- Gently pry the TPS out, watching that the pins are actually disconnected.
- Remove potting around the second pin from the bottom on the stepper motor side.
- Separate the pins so they cannot contact each other again.
- Loosen the nut on the throttle shaft, then snug it back up lightly.
- Remove the exposed non-threaded portion of the throttle shaft with a grinder or rotary tool.
- Test-fit the new TPS and check that it clears through the full throttle blade range.
- Remove the pre-loosened nut on the throttle shaft.
- Fit the new TPS magnet and test rotational alignment.
- Gently bend the pins on the new TPS so the pins touch for testing before soldering.
- Run the extra wire from the new sensor to the exposed stepper motor pin.
- Attach the new TPS, checking that the pins touch and the wire is not pinched.
- Solder the wire to the exposed throttle housing pin.
- Reassemble the throttle housing onto the car without over-tightening the screws.
- Plug in the throttle housing and scan for codes with ignition on.
- If the car starts, idles, and has no codes, continue. If not, adjust the magnet alignment and test again.
- Once the car starts and idles cleanly, remove the throttle housing.
- Optionally add thread-lock to the nut/thread, then reattach the TPS.
- Solder the three TPS pins, taking care not to melt the added wire.
- Optionally repot the pins.
- Flatten the aluminium cap and reattach it with RTV, clamping while it sets.
- Reattach the throttle housing, plug it in, reassemble the intake hoses, and test.