Parts for your 2002 Toyota Land cruiser-Oxygen sensor

2002 Toyota LandCruiser oxygen sensor: fitted on petrol models, not used on the 1HD‑FTE diesel

Technical documentation confirms oxygen sensing is relevant on the 2002 LandCruiser 100 Series when it’s the petrol 2UZ‑FE V8. Toyota’s UZJ100 Repair Manual (SFI system), Toyota Electronic Parts Catalogue, and OE supplier catalogues (DENSO/Bosch) specify two upstream air–fuel ratio (A/F) sensors and two downstream heated oxygen sensors on the V8. By contrast, the 1HD‑FTE turbo‑diesel (HDJ100) of the same year does not use exhaust oxygen sensors, Toyota’s diesel engine manual details control via boost, airflow/pressure, temperature, and injection timing without an O2 feedback sensor. So, oxygen sensors are fitted and very relevant to the 2002 petrol LandCruiser, and not used on the diesel of that era.

On the 2UZ‑FE petrol, the oxygen sensor system is the quiet achiever that keeps the big Cruiser running sweet and sipping as little fuel as a two‑and‑a‑half‑tonne wagon reasonably can. The front pair are wideband A/F sensors that constantly report how rich or lean the exhaust is, letting the ECU trim fuel on the fly for smooth running, decent economy, and tidy emissions. The rear pair are conventional heated O2 sensors, mainly there to check that the catalytic converters are doing their job.

When these sensors age, they tend to get lazy or skew readings, which can nudge the mixture rich, bump up fuel use, and eventually light the MIL with codes. Common hints include a noticeable increase in litres per 100 km, a bit of rough idle or flat spots, and fault codes like P0135/P0155 (heater circuit), P0136/P0156 (rear sensor activity), or A/F sensor performance codes. If it’s the V8 petrol, replacing tired upstream A/F sensors around the 150,000–200,000 km mark is smart preventative maintenance, especially if economy’s slipped or trims look off. The downstream sensors are usually replaced when they fault or if catalyst efficiency codes persist after other checks.

For servicing, stick with quality OE‑equivalent sensors, match the bank and position correctly, and avoid universal splice‑in leads where possible. Use the proper O2 sensor socket, undo them on a warm (not blazing hot) exhaust, and route the loom exactly as Toyota intended so it can’t chafe on the chassis or exhaust. After replacement, clear codes and let the ECU relearn trims with a good mixed drive. Off‑roaders should also eyeball the sensor wiring after water crossings or rocky tracks, a nicked harness or small exhaust leak upstream of a sensor can cause misleading readings and chase‑your‑tail diagnostics.

• Petrol 2UZ‑FE (UZJ100): 4 sensors total — 2 A/F (upstream), 2 HO2S (downstream).
• Diesel 1HD‑FTE (HDJ100): no oxygen sensors fitted.

FAQs

How many oxygen sensors does a 2002 LandCruiser have?
On the petrol 2UZ‑FE V8 there are four in total: two front air–fuel ratio sensors and two rear heated oxygen sensors. The 1HD‑FTE turbo‑diesel of the same year doesn’t use oxygen sensors at all.

When should the oxygen sensors be replaced?
There isn’t a strict time‑based interval, but many owners see benefits replacing the upstream A/F sensors at roughly 150,000–200,000 km, or sooner if there are fault codes, poor economy, or rough running. Downstream sensors are usually done when they log faults or after catalyst work.

Can the vehicle be driven with a faulty oxygen sensor?
Usually, yes, but it’ll likely use more fuel and may run less clean. Left too long, a rich mixture can overwork the catalytic converters. It’s best to sort it promptly to keep the Cruiser happy and efficient.