Parts for your 1998 Mitsubishi Lancer-Throttle position sensors

1998 Mitsubishi Lancer Throttle Position Sensor — Fitment, Purpose, and Service Tips

Technical sources confirm that a throttle position sensor (TPS) is fitted to the 1998 Mitsubishi Lancer with electronic fuel injection (CE/CK series). The Mitsubishi Motors Lancer Service Manual (CE/CK, 1996–2002, Engine & Emission Control sections) details the TPS as a 3‑wire potentiometer on the throttle body and includes diagnostics for TPS-related fault codes (e.g., P0120–P0123). Autodata technical data for the 1998 Lancer likewise shows a TPS input to the ECU and outlines test values and wiring. Haynes’ Mitsubishi Lancer 1992–2005 manual also covers TPS testing, adjustment, and replacement on these models. On that basis, the TPS is relevant and used on the 1998 Lancer in Australia and New Zealand.

On this Lancer, the TPS tells the ECU exactly how far the throttle blade is open. That signal gets used for fuel delivery, ignition timing, idle control and automatic-trans kickdown logic (where applicable). When it’s healthy, throttle response is crisp, gear changes feel right, and fuel economy stays on point.

As part of regular servicing, it’s smart to give the TPS and throttle body a bit of attention under the bonnet:

• Inspect the TPS connector and loom for brittle insulation, green corrosion or loose pins.
• Clean the throttle body bore and plate with appropriate cleaner, a sticky plate can skew TPS readings.
• If the service manual calls for it, verify the base idle switch function and TPS voltage at closed and wide-open throttle. Typical figures are outlined in the manual, use a multimeter at the sensor plug or backprobe with care.
• Scan for fault codes like P0120–P0123 and check live data for smooth percentage/voltage sweep with no flat spots.

Replacement is straightforward: disconnect the battery, unplug the sensor, remove the two screws, swap the unit, and refit. Some sensors are slotted for minor adjustment—set the closed-throttle voltage to spec if applicable. Always clear codes and perform an idle relearn if the ECU requires it. Genuine or reputable OE‑quality aftermarket sensors tend to last longer and hold calibration better, which helps keep the Lancer running sweet on Aussie and Kiwi roads.

Telltale signs the TPS is on the way out include erratic idle, hesitation on tip-in, hunting at cruise, harsh or late shifts on autos, and the check engine light. Left unchecked, it can waste fuel and make the car a pain to drive, so rolling it into the normal service routine is a good shout.

Popular questions about 1998 Mitsubishi Lancer throttle position sensors

Where is the TPS on a 1998 Lancer?
It’s mounted on the throttle body, opposite the throttle cable quadrant. Look for a small black plastic sensor with a 3‑pin plug. On most 4G1x engines, it’s accessible from the top once the intake duct is off, making checks and replacement pretty straightforward.

What symptoms point to a bad TPS on this model?
Common signs include uneven idle, flat spots on acceleration, surge at light throttle, higher fuel use, and transmission shift oddities on autos. A scan tool may show codes P0120–P0123, and live data will often reveal a jumpy or dead spot in the TPS signal when the throttle is moved slowly.

Does the TPS need adjustment or just replacement?
Some factory sensors allow fine adjustment to set the closed-throttle voltage within spec, others are fixed. If adjustment is available and the sensor tests smoothly with correct voltage at closed and wide-open throttle, it can be reused. If the signal has dead spots or spikes, replacement is the go—even perfect adjustment won’t fix internal wear.