6001549061 Oxygen O2 Sensor Vehicle Dacia LADA Renault GAZ UAZ custom

Technical Notes:

• This is a 4‑wire heated oxygen sensor manufactured to original equipment standards for Renault, Dacia, LADA and Renault Trucks vehicles.

• The four wires serve two independent circuits – two for the internal heater (power and ground) and two for the sensor signal and signal ground.

• The built‑in heating element quickly brings the ceramic sensing tip up to operating temperature after a cold start, enabling the ECU to enter closed‑loop fuel control earlier and reduce cold‑start emissions.

• Under rich (excess fuel) conditions, the sensor outputs approximately 0.6 – 1.0 V. Under lean (excess oxygen) conditions, the output falls to near 0 V. The ECU uses this feedback to continuously monitor and adjust the air‑fuel mixture.

• This sensor is installed after the catalytic converter (downstream position). Its primary function is to monitor catalytic converter efficiency by comparing its signal with the upstream sensor. The ECU uses this differential to determine whether the catalyst is operating correctly.

• As a direct‑fit sensor, it features a Renault‑Group‑specific electrical connector and pre‑terminated wiring, eliminating the need for cutting or splicing during installation.

• All sensors are 100% tested to meet or exceed original equipment quality standards. The threads are factory pre‑greased with anti‑seize compound to facilitate easier installation and prevent seizing in the exhaust bung.

The following OEM numbers are interchangeable with this Lambda Sensor. Always verify physical fitment (connector shape, pin count, cable length and thread size) with your original part before purchasing.

Cross-Reference Notes:

• The primary OE number is 6001549061, shared across the Renault‑Dacia‑LADA‑Renault Trucks group.

• 8201035691 is an alternative OE number used on some applications.

• 7960.40.040 (MTE‑THOMSON) is an aftermarket equivalent that meets the same specifications.

• Always physically compare your old sensor‘s connector shape (dedicated Renault‑Group design), pin count (4), cable length (150 mm), and thread size (M18 × 1.5) before ordering.

This Lambda Sensor is an original equipment component for vehicles manufactured within the Renault‑Dacia‑LADA Alliance. Based on available data, the sensor is installed after the catalytic converter (downstream / post‑catalyst) and is compatible with 4‑cylinder petrol engines fitted with the K7M and K4M engine families.

⚠️ Important Position Note: This is a downstream (post‑catalyst) oxygen sensor. Do not use it in the upstream (pre‑catalyst) position. Upstream and downstream O₂ sensors are not interchangeable. Using the wrong sensor in the wrong location will result in improper ECU readings, persistent fault codes and incorrect catalyst efficiency monitoring.

Fitment Verification:

• For Dacia Logan 1.6 2005 with engine K7M‑F710 (64 kW / 87 PS), the downstream oxygen sensor number is confirmed as 6001549061.

• However, always verify with your VIN (vehicle identification number). For 2005 vehicles, OE number 7700103504 may also apply; 6001549061 is the correct number for vehicles with engine serial number and VIN serial number greater than 061205.

• The sensor is factory‑supplied with a protective plastic cap and a sealing ring.

• Not compatible with diesel engines – diesel O₂ sensors use different technology (wideband / LSU) with different calibration parameters.

The vehicle fitment information above is compiled from multiple sources. Vehicle specifications may vary by production date, market region and trim level. Always confirm compatibility using your vehicle‘s VIN or by physically comparing your old sensor‘s connector shape, cable length (150 mm), pin count (4) and thread size (M18 × 1.5) before purchasing.

A faulty downstream lambda sensor degrades the ECU‘s ability to accurately monitor catalytic converter efficiency. While the engine may still run normally, emissions, fuel economy and OBD‑II readiness are all negatively affected. Replace your lambda sensor immediately if you experience any of the following symptoms.

Potential Causes of Sensor Failure:

• Normal wear and tear — Lambda sensors typically degrade after 100,000 – 160,000 km (60,000 – 100,000 miles) of operation due to continuous exposure to high‑temperature exhaust gases (up to 930 °C) and thermal cycling stress.

• Heater circuit failure — The internal heating element opens or shorts. This causes the sensor to respond extremely slowly or not at all when cold, triggering heater‑related fault codes.

• Contamination (“sensor poisoning”) — Oil, coolant, silicone‑based sealants, or the use of leaded fuel permanently coats the ceramic sensing tip, destroying its ability to detect oxygen.

• Physical impact damage — Dropping the sensor (even from a low height) or impact from road debris can crack the fragile ceramic element.

• Wiring / connector issues — Damaged wiring, loose connections, corrosion at the connector, or an intermittent open / short circuit can trigger fault codes even when the sensor itself is healthy.

• Exhaust leaks near the sensor bung — False oxygen readings from an exhaust leak will cause erratic sensor output and may be incorrectly attributed to a faulty sensor.

• Catalytic converter failure — A failed catalytic converter can accelerate downstream sensor degradation or produce the same fault codes as a failed sensor.

Diagnostic Tips:

• P0420 (Catalyst System Efficiency Below Threshold) is the most common code associated with downstream sensor failure. However, P0420 can also indicate a failing catalytic converter.

• How to differentiate: If the downstream sensor‘s voltage readings are too similar to those of the upstream sensor (both fluctuating rapidly), the catalytic converter is likely no longer functioning properly. If the downstream sensor voltage is stuck high, stuck low, or shows no activity, the sensor itself is likely faulty.

• A single P0420 with no sensor circuit codes and normal fuel trims leans toward a worn catalyst; multiple sensor circuit or heater codes (P0136‑P0141, P0036‑P0037) point to a failed downstream O₂ sensor or wiring problem.

• To diagnose a faulty sensor:

  • Heater circuit test: Use a digital multimeter to measure the resistance across the two heater circuit pins. A healthy sensor should read within the expected specification (consult your vehicle‘s service manual). An open circuit (infinite resistance) or short circuit (0 Ω) indicates heater failure.

  • Sensor signal test: Use an OBD‑II scanner to monitor the downstream sensor voltage output under steady‑state driving. A healthy downstream sensor should show a relatively stable voltage signal that is distinct from the upstream sensor‘s fluctuating output. If the downstream sensor‘s voltage mirrors the upstream sensor‘s fluctuating signal, the catalytic converter may be failing, or the downstream sensor may be faulty.

• Always investigate the root cause before replacing the sensor — if contamination caused the failure, replacing the sensor without addressing the underlying issue will result in repeated premature failure.

Fault code information based on OBD‑II standardised diagnostic trouble code definitions and automotive diagnostic resources.

1. Confirm Fitment – Physical Inspection is Essential

• This is a direct‑fit downstream sensor with a 4‑pin Renault‑Group‑specific connector, 150 mm cable length, M18 × 1.5 thread, and 22 mm (7/8″) spanner size.

• ⚠️ Do not purchase based solely on the OE number. Aftermarket equivalents may have differences in cable length, connector shape, or calibration parameters. If the connector does not match, do not install.

• Physically compare your original sensor‘s connector shape (dedicated Renault / Dacia / LADA design), pin count (4), cable length (150 mm), and thread size (M18 × 1.5) before ordering.

• Measure the cable length of your original sensor — this sensor has a very short 150 mm cable designed specifically for the downstream bung position close to the connector. A different cable length may not reach the harness.

2. Verify Sensor Position – Downstream / Post‑Catalyst Only

• This sensor is designed for the downstream (post‑catalyst) position as a diagnostic probe (Bank 1, Sensor 2). It should be installed after the catalytic converter.

• Upstream (pre‑cat) and downstream (post‑cat) O₂ sensors are not interchangeable. Replacing an upstream sensor with a downstream unit (or vice versa) will result in improper ECU readings, persistent fault codes, and the ECU may not be able to correctly monitor catalyst efficiency.

• How to verify: Locate your vehicle‘s catalytic converter. The downstream sensor is installed in the pipe after the catalytic converter — follow the exhaust pipe from the rear of the converter to find the downstream sensor. It typically sits close to the connector bracket, which is why the cable length is only 150 mm. If your faulty sensor is located before the converter, this part is not suitable for your application.

• For vehicles with two oxygen sensors (common in Euro‑3/Euro‑4 engines), this part is for the rear (post‑cat) position. The front (pre‑cat) sensor requires a different part number (e.g., for Logan 1.6 with K7M‑F710, the upstream sensor number may be 7700103504 or similar).

3. Replacement Interval

• Lambda sensors degrade gradually over time, often without triggering immediate fault codes. Their switching response becomes slower and their voltage range narrows with age and mileage.

• Proactive replacement at 160,000 km (approx. 100,000 miles) is recommended to maintain optimal catalytic converter health, proper emissions output, and correct OBD‑II monitor readiness.

• Even if no Check Engine Light is present, an aged sensor will still respond more slowly than a new one, affecting catalyst monitoring accuracy. Proactive replacement can help prevent premature catalytic converter failure — a much more expensive repair than the sensor itself.

4. Installation Tips

Before Installation:

• Allow the exhaust system to cool completely before removal — the catalytic converter remains dangerously hot for up to 30 minutes after engine shutdown. Attempting removal on a hot system risks severe burns.

• Disconnect the vehicle‘s battery negative (-) cable before starting work to prevent electrical issues, potential ECU damage, or accidental short circuits.

• Use a high‑quality O₂ sensor socket (22 mm / 7/8″) with an offset design to prevent stripping the sensor‘s flats and to provide better access in confined underbody areas. A standard deep socket can easily damage the sensor housing or its flats.

Removal of the Old Sensor:

• Apply penetrating oil (e.g., WD‑40) to the threads of the old sensor the night before removal. This can significantly ease extraction, especially if the sensor has been installed for many years in the harsh exhaust environment.

• If the sensor is difficult to remove when cold, it may be easier when the exhaust is warm (run the engine for 1‑2 minutes, then allow it to cool until it is warm but not scalding). Exercise extreme caution to avoid burns — wear heavy‑duty heat‑resistant work gloves.

• Do not use excessive force — damage to the exhaust bung threads can result in expensive repairs, potentially requiring exhaust component replacement or thread repair (helicoil / timesert).

• Disconnect the electrical connector carefully — press the locking tab and pull only the connector housing (never pull directly on the wires). The connector bracket is typically located near the downstream bung on the underbody.

• Inspect the old sensor‘s connector, cable, and tip for signs of contamination (oil, soot, coolant residue), melting, or cracking. Note any contamination — this indicates an underlying engine issue that must be addressed before installing the new sensor to prevent repeat failure.

Installation of the New Sensor:

• Do not apply additional anti‑seize compound unless the new sensor‘s threads are completely dry. Many OE‑quality sensors are factory‑coated with anti‑seize. Adding extra can contaminate the sensor tip and cause premature failure. If the threads appear dry and no pre‑grease is evident, apply a small amount of sensor‑safe anti‑seize compound to the threads only — never to the sensor tip.

• Do not use silicone sealants anywhere near the exhaust system — silicone vapour will permanently contaminate and destroy the oxygen sensor (this is one of the most common causes of premature failure and is almost always non‑warrantable).

• Avoid touching the sensor tip — skin oils contain salts and contaminants that can damage the ceramic sensing element, causing inaccurate readings and premature failure. Always handle the sensor by the hexagon nut or connector body.

• Do not drop the sensor — the ceramic element inside the metal housing is brittle and can crack upon impact, rendering the sensor inoperative even if no external damage is visible.

• Tighten to the correct torque — typical torque for an M18 × 1.5 oxygen sensor is 40 – 50 Nm (30 – 37 ft‑lb) . Use a torque wrench to avoid overtightening or undertightening.

  • CAUTION: Overtightening can damage threads in the exhaust bung and may crack the sensor housing. Undertightening may cause exhaust leaks and false oxygen readings.

• Route the wiring harness securely using the original clips and routing guides to prevent contact with hot exhaust components (catalytic converter, exhaust pipe) or moving parts (drive shafts, steering components). The very short cable length (150 mm) is specifically designed for the downstream bung position — do not try to stretch or force the cable beyond its intended reach.

• Reconnect the electrical connector fully — an audible click confirms correct engagement. Ensure the locking tab is fully seated and locked into place.

• Reconnect the vehicle‘s battery after installation is complete.

Post‑Installation:

• Start the engine and allow it to reach normal operating temperature (closed‑loop mode). This typically takes 5‑10 minutes of driving or idling.

• Verify that no exhaust gas leakage exists around the sensor bung (listen for “puffing” sounds, or use a soap‑and‑water solution sprayed around the threads — bubbles indicate a leak).

• Use an OBD‑II scanner to clear any existing fault codes (old codes stored in the ECU must be cleared to turn off the MIL and reset monitors).

• Drive the vehicle through a complete drive cycle (typically 10‑20 minutes of mixed driving: stop‑start traffic, steady cruising at 50‑60 mph, moderate acceleration and deceleration) to allow the ECU to re‑learn adaptation values and complete oxygen sensor and catalyst monitors.

• After the drive cycle, re‑scan for fault codes to confirm that the oxygen sensor monitors have completed and that no new codes have appeared.

5. Required Tools

6. Quantity Needed — Downstream Sensor

• 4‑cylinder Renault / Dacia / LADA / GAZ / UAZ petrol engines typically have two oxygen sensors: one upstream (pre‑cat / regulating) and one downstream (post‑cat / diagnostic) — this part is for the downstream position.

• If your vehicle has covered more than 100,000 km and the Check Engine Light is present with code P0420, it is common practice to replace the downstream oxygen sensor proactively.

7. Professional Installation Recommended

• While this is a direct‑fit part, professional installation is strongly recommended if you are not experienced with exhaust system work or if the sensor is located in a difficult‑to‑reach position.

• After replacement, the ECU may need to have adaptation values reset using manufacturer‑specific diagnostic equipment (e.g., Renault CLIP, Dacia diagnostic tools).

• Improper installation can lead to:

  • Exhaust leaks around the sensor bung

  • Cross‑threaded or damaged exhaust bung threads — expensive to repair, possibly requiring exhaust pipe replacement

  • Sensor damage from contamination or mishandling (touching tip, dropping, silicone exposure)

  • Wiring damage from contact with hot exhaust components or moving parts

  • Persistent ECU fault codes despite a correctly functioning sensor

8. Warranty

• Genuine Renault OE parts typically include a manufacturer warranty through authorised dealers — commonly 12 months.

• Aftermarket equivalents may offer varying warranty periods — commonly 1 to 2 years. Some premium aftermarket sensors carry extended warranties (e.g., 3‑year / 60,000‑mile coverage). Check with your specific retailer for their warranty terms and return policy.

• Important: Most warranties are voided if the sensor tip shows contamination from improper handling (e.g., touching the tip, dropping the sensor, silicone exposure, or installation with contaminated hands or tools). Oxygen sensors are often non‑returnable except for approved warranty replacement due to contamination risk.

• Keep your original packaging until the new sensor is installed and confirmed working — you may need it for warranty claims or returns.

9. Common Mistakes to Avoid