Error P0420 on your dashboard Nissan - one of the most common problems associated with the exhaust system. This code points to low catalytic converter efficiency (jar 1), which often becomes a headache for model owners Qashqai, X-Trail, Juke and even GT-R. But what exactly is hidden behind this error? Why does it appear and how to properly eliminate it without wasting money?
In this article we will look at real reasons for P0420 on Nissan, which car services often keep silentto sell you a new catalyst. You'll learn how to diagnose the problem yourself, which parts to check first, and when the catalytic converter actually needs to be replaced. And also - how to deceive the system and reset the error if the budget is limited. But remember, ignoring P0420 can have serious consequences for your engine and fuel system.
What does code P0420 mean on Nissan?
Code P0420 stands for Catalyst System Efficiency Below Threshold (Bank 1) — that is, the efficiency of the catalyst in the first bank (bank of cylinders) is below the permissible threshold. B Nissan this code is set when the engine control unit (ECU) detects that the catalytic converter is not cleaning the exhaust gases as well as it should.
How does it work? Two oxygen sensor (lambda probes) - upper (before the catalyst) and lower (after it) - compare the oxygen level in the exhaust. If the difference between their readings is too small, ECU concludes that the catalyst does not perform its function. The normal difference should be 0.1–0.9 V when the engine is running at 2500 rpm.
It is important to understand that P0420 is not a death sentence for the catalyst. In 40% of cases the problem lies in oxygen sensors, wiring or even ECU firmware. For example, on Nissan Almera N16 And Primera P12 this error often occurs due to “glitches” of the control unit after chip tuning.
- Qashqai
- X-Trail
- Juke
- Almera
- Teana
- Other
The main causes of error code P0420 on Nissan
Before you run to the store for a new catalyst (which can cost from 20 to 150 thousand rubles), check these 7 most likely reasons P0420 errors:
- 🔥 Worn or melted catalyst — over time, cells become clogged or destroyed, which reduces throughput.
- 🔌 Faulty lower lambda probe (after the catalyst) - gives false readings, which is why ECU “thinks” that the catalyst is not working.
- ⚡ Problems with sensor wiring — oxidized contacts or open circuits distort the signal.
- 🛢️ Bad fuel or additives — low-quality gasoline with a high sulfur content “poisons” the catalyst.
- 🔧 Exhaust leaks in front of the catalyst (for example, a burnt-out manifold or gasket).
- 💻 Incorrect ECU firmware — after chip tuning or software updates, the threshold values may be lost.
- 🚗 Mechanical damage - a blow to the exhaust system or corrosion can destroy the catalyst.
On models Nissan Qashqai J10/J11 And X-Trail T31/T32 most often it is the fault lower lambda probe (part code: 22690-4M000 or 22690-4M010). Its resource rarely exceeds 100–120 thousand km. And on Nissan Juke with engine HR16DE the problem is often related to overheating of the catalyst due to faulty spark plugs.
Before replacing the catalyst, be sure to check the spark plugs and coils! Malfunctions in the ignition system lead to unburned fuel entering the exhaust, which “kills” the catalyst within 5–10 thousand km.
How to Diagnose P0420 Yourself
To avoid paying for service diagnostics, you can check a few key points yourself. For this you will need:
- 🔧 OBD-II scanner (even the simplest one for 1000 rubles).
- 🔍 Multimeter to check sensors.
- 📱 Phone with Torque Pro app (or similar).
Step 1: Connect the scanner and check lambda probe readings in real time. Normal values:
- 🔹 Upper sensor (before the catalyst): ranges from
0.1 to 0.9 V(1-2 times per second). - 🔹 Lower sensor (after catalyst): stable
0.6–0.7 V(small fluctuations).
If the lower sensor “jumps” the same way as the upper one, the catalyst is not working.
Step 2: Check wiring integrity sensors Often the contacts oxidize or rub against the exhaust pipe. Especially relevant for Nissan Note And Micra, where the wires go without protection.
Check the readings of the lambda probes with a scanner | Inspect the wiring for damage | Listen to the exhaust for leaks | Check the spark plugs and ignition coils | Visually assess the condition of the catalyst (if possible)-->
Is it possible to drive with P0420?
Technically, yes, the car will drive. But there is 3 serious risks, about which few people warn:
⚠️ Attention! On Nissan with MR20DD, QR25DE and VQ35DE engines Driving for a long time with P0420 may cause overheating and detonation due to the disturbed composition of the fuel mixture. This is fraught engine overhaul (from 200 thousand rubles).
- 🔥 Increased fuel consumption - up to
+2–3 l/100 km, since ECU goes into emergency mode. - 🚗 Power reduction — the car accelerates worse, especially at low speeds.
- 💰 Accelerated catalyst wear - if the problem is in the sensors and you do nothing, the catalyst honeycombs may melt.
In practice: if the error appears for the first time, you can go to the service center. But if Check Engine is constantly on fire more than 2 weeks - It’s better not to delay repairs. For example, on Nissan Pathfinder R51 ignoring P0420 often results in exhaust system blockage, which results in replacing the entire tract (from 80 thousand rubles).
Troubleshooting P0420
Depending on the reason, there is 5 main ways solve the problem. Let's look at them in order - from cheapest to most expensive:
| Method | Cost (RUB) | When to use | Risks |
|---|---|---|---|
| Resetting an error with a scanner | 0 (if there is a scanner) | The error appeared for the first time after refueling with bad gasoline. | Will return if problem persists |
| Replacing the lower lambda probe | 3 000–8 000 | The sensor is faulty or giving incorrect readings | If the catalyst is truly faulty, the error will remain |
| Cleaning the catalyst | 5 000–15 000 | The honeycombs are clogged but not destroyed | Will not help with melting or mechanical damage |
| Installing a decoy or emulator | 2 000–10 000 | The catalyst has been removed, but the ECU needs to be tricked | Illegal for MOT, may cause other errors |
| Catalyst replacement | 20 000–150 000 | Honeycombs are melted or destroyed | Expensive, but the only legal way |
On Nissan Tiida And Almera Classic often helps replacing the lower lambda probe (original: 22690-4M000, analogue: NGK 90996). And on Nissan X-Trail T32 with engine MR20DD often required ECU firmware, since standard software is too sensitive to sensor fluctuations.
How to check a lambda probe with a multimeter?
1. Warm the engine to operating temperature.
2. Connect the multimeter leads to the sensor signal wire (usually black or gray) and ground.
3. At idle speed the voltage should range from 0.1 to 0.9 V.
4. If the readings are stable (for example, 0.45 V), the sensor is faulty.
5. Check the resistance of the sensor heater (should be 2–14 ohms).
Cheats and emulators: is it worth the risk?
Many owners Nissan are considering catalyst decoys as a budget solution. But there is 3 key nuances:
⚠️ Attention! On Nissan with EOBD2 systems (Euro-4 and higher) simple mechanical tricks (in the form of a spacer) work only in 30% of cases. ECU analyzes not only the signal of the second sensor, but also response time, which is difficult to emulate.
- 🔧 Mechanical snag — welded in place of the catalyst, creates a signal delay. Worth it
2,000–5,000 rub., but may not pass MOT. - 💻 Signal emulator — connects to the sensor wiring, simulates the operation of the catalyst. Price:
8,000–15,000 rub.. - 📉 ECU flashing — disables the catalyst check in the software. Cost:
10,000–25,000 rub..
On Nissan Juke And Qashqai with engines HR16DE And MR20DD mechanical tricks often cause an error P0430 (sensor heating circuit malfunction). In such cases it is better to use emulators with microprocessor, for example, Catalyst Simulator Pro.
Important: starting from 2023, Russia has tightened the requirements for the environmental class of cars. Cars without a catalyst or with decoys can fail inspection, if the test is carried out on a gas analyzer.
Catalyst tricks are a temporary solution. If you plan to operate the car for a long time, it is better to replace or repair the catalyst legally.
How much does a repair cost: prices for parts and labor
The cost of repairing a P0420 code varies greatly depending on the model. Nissan and the chosen method of elimination. Below are the current prices for 2026 for popular models:
| Model Nissan | Replacing the lambda probe (lower) | Cleaning the catalyst | Replacing the catalyst (original) | Decoy/emulator |
|---|---|---|---|---|
| Qashqai J11 (MR20DD) | 5 000–8 000 | 8 000–12 000 | 45 000–70 000 | 3 000–10 000 |
| X-Trail T32 (MR20DD) | 6 000–9 000 | 10 000–15 000 | 50 000–80 000 | 4 000–12 000 |
| Juke (HR16DE) | 4 000–7 000 | 7 000–10 000 | 35 000–60 000 | 2 500–9 000 |
| Almera N16 (QG16DE) | 3 000–5 000 | 5 000–8 000 | 20 000–40 000 | 2 000–7 000 |
| Pathfinder R51 (VQ40DE) | 7 000–10 000 | 12 000–18 000 | 60 000–100 000 | 5 000–15 000 |
Tip: On models older than 2010 (for example, Nissan Teana J32) can be saved by installing universal catalyst instead of the original one. For example, Bosch 0986AA3010 or Walker 80736 will cost 15,000–25,000 rub. instead of 50 000+ for the original.
The work to replace the catalyst in the service costs 3,000–8,000 rub., but if you have welding and skills, you can do it yourself. The main thing is not to forget reset error scanner after replacement!
FAQ: Frequently asked questions about error code P0420 on Nissan
Can P0420 be reset by simply disconnecting the battery?
No, this won't help for long. The error will return after 10–50 km, as the problem has not been resolved. Disconnecting the battery only resets current codes in memory ECU, but does not correct the cause. On Nissan Note And Micra after such a reset an error may appear P0100 (air flow meter circuit malfunction).
What kind of gasoline should I fill in so as not to damage the catalyst?
For Nissan It is recommended to use at least gasoline AI-95 (Euro-5). On models with turbo engines (GT-R, Juke 1.6T) - only AI-98. Cheap gasoline with an octane rating of 92 or low additive content leads to:
- 🔥 Overheating of the catalyst due to detonation.
- 🧪 Clogging hundreds with sulfur and lead.
- ⚡ Damage to lambda probes.
If error P0420 appears after refueling, try burn off deposits: Drive 20–30 km at high speed (3000–4000 rpm).
What happens if you remove the catalyst and do not install the blende?
Without catalyst and blende ECU will constantly record error P0420, and the car will go into emergency mode. Consequences:
- 🔥 Increased fuel consumption (
+15–20%). - 🚗 Reduction in power (especially noticeable on Nissan with VQ35DE engines).
- 💨 Failure to pass technical inspection (exceeding CO/CH in the exhaust).
- ⚠️ Risk of damage to the second lambda probe (due to high temperature).
On Nissan Patrol Y61 And Navara D40 Removing the catalyst without blende can lead to overheating of the exhaust manifold and cracks in it.
How often do you need to change the catalyst on a Nissan?
The service life of the catalyst depends on operating conditions:
- 🚗 City mode (frequent short distance trips):
80–120 thousand km. - 🛣️ Route (long trips at high speeds):
150–200 thousand km. - ⛽ Bad fuel: resource is reduced to
50–80 thousand km.
On Nissan Murano Z51 And Maxima A35 catalysts last longer thanks to a more advanced injection system. And on Almera Classic And Sunny they have to be changed already 60–90 thousand km.
Is it possible to clean the catalyst with your own hands?
Yes, but only if the honeycombs are not melted. Methods:
- Flushing with special liquid (For example, Liqui Moly Pro-Line Katalysator Reiniger). Cost:
1,500–2,500 rub.. - Ultrasonic cleaning (in the service). Price:
5,000–10,000 rub.. - Mechanical cleaning (air blowing + brush). Risk of damaging the cells!
On Nissan Tiida And Juke cleaning helps in 60% of cases if the problem is not advanced. But on X-Trail T31 with mileage >150 thousand km, replacement is usually required.