Symptoms
Stalling, rough idle or random check-engine lights. Quadratec's example was a TJ throwing P0122 that stalled while driving; automatics rely on the TPS to run properly. Aging crankshaft-position, throttle-position and oxygen sensors are all common failures.
The fix, step by step
- For the TPS: disconnect the negative battery terminal, then unplug the TPS, IAC motor and MAP sensor connectors.
- Remove the intake tube and unclip the throttle cable (plus the kickdown and cruise cables where fitted).
- Remove the four throttle-body bolts, take the TPS off with a T25 Torx, fit the new sensor with the supplied hardware, and refit the throttle body, replacing the gasket if it's tired.
- For a crank sensor, Mopar's 4727451AA is listed for 2003–06 4.0 TJs.
Tools & part numbers
- 13 mm (or 1/2 in) socket for the battery
- 5/16 in driver
- 10 mm socket
- T25 Torx
- code reader.
Where to buy the parts
Mopar 68404428AA throttle position sensor, 2002–06 TJQuadratec ↗Amazon ↗
Mopar 4727451AA crankshaft position sensor, 2003–11 TJ 4.0 & JK 3.8Quadratec ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Wrangler Unlimited (LJ) parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.