Error P1165 on Nissan Skyline: complete analysis of the problem with the oxygen sensor

Error P1165 on Nissan Skyline - one of those problems that can unsettle even experienced car owners. This fault code is directly related to the air-fuel mixture control system, or more precisely, to oxygen sensor heater circuit (bank 2, sensor 1). If your on-board computer or OBD-II scanner shows this code, you cannot ignore it: the consequences can range from increased fuel consumption to serious damage to the catalytic converter.

In this article we will look in detail at what is hidden behind the error. P1165 is specific to Skyline models (including R32, R33, R34 and V35/V36), how to correctly diagnose it without extra costs, and what steps to take to eliminate it. We will pay special attention to the typical pitfalls that owners encounter when doing their own repairs, as well as the nuances associated with engine modifications RB20DET, RB25DET And VQ35DE.

What does error code P1165 mean on Nissan Skyline?

Code P1165 stands for «Heated Oxygen Sensor (HO2S) Heater Performance Bank 2 Sensor 1». Translated into practical language, this means that the engine control unit (ECU) detected a malfunction heating element of the first oxygen sensor, located after the catalytic converter on the second bank of cylinders (for V-shaped engines).

Why is this critical? The oxygen sensor (lambda probe) must quickly warm up to operating temperature (~600°C) in order to correctly measure the oxygen content in the exhaust gases. If the heater fails, the sensor begins to “lie”, and ECU goes into emergency mode, enriching or leaning the mixture “blindly”. For Skyline with turbo engines this is fraught with:

• 🔥 Catalyst overheating due to incorrect composition of the mixture;
• ⚡ Power drop and “dull” response to the gas pedal;
• ⛽ Increased fuel consumption by 10–25%;
• 🚨 Risk of turbine damage (relevant for RB25DET And RB26DETT).

On models Skyline V35/V36 with engines VQ35DE error P1165 often accompanied by additional codes such as P0136 or P0156, indicating a systemic problem with the oxygen sensors. It is important to understand: ignoring this error may lead to cascading failures at work ECU, especially if the car is equipped with a system Nissan Consult.

Causes of error P1165

Specifics Nissan Skyline is that the error P1165 can be caused by both mechanical faults and software glitches. Let's consider the main reasons, ranked by frequency of occurrence:

1. Malfunction of the lambda probe heating element. Over time, the heater coil oxidizes or breaks due to vibration or overheating. On Skyline R33/R34 This is a common problem due to the age of the vehicles.
2. Poor contact or broken wiring. The wires going to the sensor may rub against the exhaust manifold or become corroded. Connectors on sensors are especially vulnerable Denso And NTKinstalled from the factory.
3. Sensor contamination with combustion products. If the engine “eats” oil (relevant for RB26DETT with a mileage of 100 thousand km), soot clogs the working surface of the sensor, preventing it from warming up.
4. Malfunction of the control unit (ECU). Rarely, but it happens that ECU generates false errors due to damage to the power supply circuits or firmware.
5. Engine weight problems. On Skyline V35 the weak point is the mass attached to the cylinder head. Oxidation of the contact leads to unstable power supply to the sensors.

Interesting fact: on Skyline GT-R (R32–R34) error P1165 sometimes appears after installing non-original exhaust systems (for example, HKS Hi-Power or Tomei Expreme). The reason is a change in the temperature regime of the exhaust gases, for which the standard sensor is not designed. In such cases, it is necessary to replace the lambda probe with broadband (For example, Innovate LC-2).

How to check the power supply to the sensor heater?

To check the voltage supply to the lambda probe heater:

1. Disconnect the sensor connector.

2. Turn on the ignition (without starting the engine).

3. Measure the voltage between the heater pins (usually pins 3 and 4 on the sensor connector Denso).

4. Normal value: 12-14 V. If there is no voltage, check the fuse EFI (15A) and sensor heater relay.

Diagnosing error P1165: step-by-step instructions

To pinpoint the cause P1165, you will need a multimeter, an OBD-II scanner (for example, Launch CReader or ELM327) and basic electrical skills. Follow this algorithm:

Read all errors with a scanner (there may be several codes)|Check the integrity of the sensor wiring (visually and with a multimeter)|Measure the resistance of the lambda probe heater|Check the supply voltage at the sensor connector|Inspect the sensor for mechanical damage-->

Step 1: Read Errors

Connect the scanner to the connector OBD-II (on Skyline R34 it is located under the steering column, on V35 - next to the brake pedal). Write down all trouble codes. If in addition P1165 There is P0130–P0167, the problem is systemic and requires an integrated approach.

Step 2: Check Wiring

Disconnect the oxygen sensor connector (bank 2, sensor 1 - usually the right sensor on V-twin engines). Inspect the wires for:

• 🔥 Melts or abrasions (especially near the exhaust manifold);
• 💧 Traces of corrosion in the connector;
• 🔌 Reliable fixation of contacts (sometimes they “fall out” of the plastic case).

Step 3: Sensor Heater Test

Set the multimeter to resistance (Ω) measurement mode and connect the probes to the heater contacts (see diagram for your model Skyline). Normal values:

Sensor model	Heater Resistance (Ω)	Notes
Denso DOX-0109 (original for RB25DET)	2–10 Ω	If the resistance is >20 Ω, the sensor must be replaced
NTK 25071 (analogue for VQ35DE)	3–7 Ω	Sensitive to overheating, often fails when tuning the exhaust
Bosch 0 258 006 537 (universal)	4–12 Ω	Requires adaptation with ECU on some firmwares

Step 4: Check Power

Turn on the ignition and measure the voltage at the heater power contacts (usually +12V and ground). If there is no voltage, check:

• 🔋 Fuse EFI (15A) in the fuse box;
• 🔌 Sensor heater relay (on Skyline R33 it is located behind the glove compartment);
• 🔧 Engine mass integrity (clean the contact on the block head!).

How to fix error P1165: from simple to complex

Depending on the diagnostic results, solutions P1165 can be divided into three categories: simple (available to beginners), average (requires a tool) and complex (it’s better to leave it to professionals).

1. Simple solutions (5–30 minutes)

• 🔌 Cleaning the connector contacts. Use contact spray CRC or WD-40 to remove oxides. On Skyline R34 The connector often oxidizes due to its close location to the turbine.
• 🔧 Replacing the fuse. fuse EFI may burn out due to a power surge. Check its integrity.
• 🛠️ Reset ECU. Sometimes the error occurs due to a temporary glitch. Disconnect the negative terminal of the battery for 10 minutes, then reset the errors using the scanner.

2. Medium solutions (1–3 hours)

• 🔧 Replacing the oxygen sensor. If the heater is faulty, the sensor must be replaced. For Skyline original recommended Denso or NTK. Cost: 3,000–8,000 rubles.
• 🔥 Wiring repair. If the wires are frayed, they can be soldered and insulated with heat shrink tubing. It is important to use high temperature insulation (up to 200°C).
• 🔋 Cleaning the engine mass. On V35/V36 The mass is attached to the cylinder head under the intake manifold. Clean the contact with sandpaper and treat Lithol.

3. Complex decisions (require experience)

• 🔧 Replacing or flashing ECU. If the control unit produces false errors, it may require repair or flashing (relevant for tuned Skyline GT-R).
• 🔥 Exhaust system modification. When installing a forward flow or sports manifold, it may be necessary to replace the lambda probes with broadband ones and adapt ECU.
• 🛠️ Fuel system diagnostics. If the error is accompanied by a code P0171 (lean mixture), check the injectors, fuel pump and pressure regulator.

Common repair mistakes and how to avoid them

Many owners Nissan Skyline encounter a relapse of the error P1165 after a seemingly successful renovation. Here are the most common mistakes and how to prevent them:

⚠️ Attention: On Skyline V35 with VQ35DE Oxygen sensors from other models cannot be used Nissan (for example, from 350Z), even if they are visually identical. Differences in heater calibration will cause the problem to reoccur. P1165.

1. Using non-original sensors

Cheap analogues (for example, Chinese No-Name) often have heater resistance outside the acceptable range. This leads to the fact that ECU The error is detected within 1–2 weeks. Always check the resistance of a new sensor before installation!

2. Ignoring engine mass

On RB26DETT the mass is attached to the cylinder block under the turbine. Over time, the contact oxidizes and the voltage on the sensor heater drops. Be sure to clean the ground when doing any electrical work!

3. Incorrect sensor installation

When replacing a lambda probe, many people forget to apply non-stick paste (For example, Bosch 0 261 945 800) on the thread. This leads to “sticking” of the sensor and its breakdown during the next dismantling. Also, do not overtighten the sensor - tightening torque: 40–50 Nm.

4. Antifreeze getting into the exhaust

If the error P1165 accompanied by white smoke from the exhaust pipe, check the cylinder head gasket. Antifreeze, getting into the exhaust, destroys the working element of the sensor in a few days.

Cost of repairs and where is the best place to get them repaired

The cost of fixing the error P1165 depends on the cause and region. Let's consider the estimated costs for Moscow and the regions (for 2026):

Type of repair	Cost (Moscow, ₽)	Cost (regions, ₽)	Notes
Diagnostics with a scanner	1 000–1 500	500–1 000	Includes reading errors and checking sensor parameters
Replacing the oxygen sensor (1 pc.)	3 000–6 000	2 000–4 000	Cost including labor, original sensor Denso
Wiring repair	2 000–4 000	1 500–3 000	Includes soldering, insulation and circuit testing
Cleaning the engine mass	500–1 000	300–800	Often included in complex diagnostics
ECU firmware (for false errors)	5 000–15 000	4 000–10 000	Relevant for tuned cars

Where is the best place to have it repaired?

• 🔧 Official dealers Nissan. Plus: warranty on work, original spare parts. Disadvantage: high price (diagnostics from 2,500 ₽).
• 🔧 Specialized services for Skyline. For example, JDM Garage or RB Service in Moscow. Plus: experience with a specific model. Minus: not available everywhere.
• 🔧 DIY repair. Suitable for replacing the sensor or cleaning contacts. Disadvantage: risk of damaging connectors or misdiagnosing the problem.

⚠️ Attention: On Nissan Skyline GT-R (R32–R34) with the system ATTESA E-TS Incorrect operation of oxygen sensors can lead to malfunctions in the distribution of torque along the axes. If, after replacing the sensor, the car “stumbles” at the start, an adaptation reset is required ECU through Nissan Consult.

Preventing error P1165 on Nissan Skyline

Prevent occurrence P1165 easier than eliminating its consequences. Here are the key preventive measures:

1. Regular check of sensors. Every 30,000 km, inspect the lambda probe connectors for corrosion and mechanical damage. On Skyline With a mileage of >100 thousand km, it is recommended to change the sensors preventively.
2. Using quality fuel. Bad gasoline with a high sulfur content reduces the service life of sensors by 2–3 times. For RB26DETT minimum octane is 98.
3. Oil control. If the engine “eats” oil (>1 liter per 1,000 km), soot quickly damages the lambda probes. Check valve stem seals and rings.
4. Wiring protection. Wrap the sensor wiring harnesses with heat-resistant tape (such as 3M Super 33+) to protect against chafing.
5. Prevention of mass. Once a year, clean the engine ground contacts and treat them Litolom-24.

For owners of tuned Skyline:

• 🔥 When installing a sports exhaust (e.g. N1-style) replace the standard sensors with broadband (For example, Innovate LC-2).
• 🔧 After chip tuning (Power FC, Haltech) be sure to calibrate the sensors via software ECU.
• ⚡ Use isolation relays to power sensor heaters if you install additional equipment (for example, GReddy e-Manage).

💡

On Nissan Skyline R33 with engine RB25DET The P1165 code may be due to a faulty sensor heater relay (located under the hood near the battery). Before replacing the sensor, check this relay - its contacts often burn out!

FAQ: Frequently asked questions about error P1165

Is it possible to drive with P1165?

Short term - yes, but not recommended. Driving for a long time with a faulty oxygen sensor leads to:

• Increased fuel consumption (up to +30%);
• Overheating and failure of the catalytic converter;
• Risk of damage to the turbine (at RB25DET And RB26DETT).

If the error appears for the first time, you can go to the service center, but do not put off repairs for long.

Which oxygen sensor is better to install on Skyline?

Recommended options:

• Denso DOX-0109 - original for RB-series;
• NTK 25071 - original for VQ35DE;
• Bosch 0 258 006 537 - universal analogue (requires adaptation).

Avoid cheap Chinese sensors - they last no more than 10,000 km.

Can P1165 appear after washing the engine?

Yes, especially on Skyline V35/V36. Water enters the sensor connector, causing corrosion or a short circuit. To avoid the problem:

• Before washing, disconnect the sensor connectors;
• After washing, dry the connectors with compressed air;
• Apply dielectric grease (such as CRC 2-26).

Do I need to reset errors after replacing the sensor?

Yes, but not right away. After replacement:

1. Start the engine and let it idle for 5–10 minutes;
2. Drive 20–30 km in mixed mode (city + highway);
3. Only then clear the errors using the scanner.

This is necessary to ECU “learned” new sensor parameters.

Could P1165 be caused by a bad turbo?

Indirectly - yes. If the turbine “drives” oil into the intercooler or exhaust system (due to wear on the seals), this leads to:

• Contamination of the oxygen sensor with soot;
• Oil getting on the heating element, which causes its failure;
• False signals ECU about lean/rich mixture.

If together with P1165 there are errors on the turbine (P0234, P0256), diagnose it first.