Owners Nissan Murano (especially models Z50 And Z51 with gasoline engines VQ35DE And VQ25DE) often encounter the problem of clogged catalysts. Symptoms are known: loss of power, error P0420 (“low efficiency of the catalytic converter”), increased fuel consumption. Against this background, removing catalysts seems like a logical solution - cheap and fast. But is this really so?

In this article we will analyze all aspects of catalyst removal on Murano: from technical nuances to legal consequences. You will find out what hidden risks fraught with the procedure, how it affects engine life, and why some mechanics refuse to carry it out. We will also provide step-by-step instructions for those who have decided to take this step, and alternative ways to solve the problem.

Why do catalysts fail on Nissan Murano?

Catalytic converter service life Nissan Murano rarely exceeds 120–150 thousand km. This is due to several factors:

  • 🔥 Fuel quality: Russian gasoline with a high sulfur content and additives accelerates the “poisoning” of the catalyst honeycomb.
  • 🛢️ Oil zhor: motors VQ35DE prone to oil consumption (especially after 150 thousand km), which burns and clogs the honeycombs with soot.
  • 🔧 Ignition system malfunctions: misfires lead to overheating of the catalyst and its destruction.
  • ❄️ Short trips in winter: frequent cold starts do not allow the catalyst to warm up to operating temperature, which shortens its life.

The first signs of trouble are Check Engine with an error P0420 or P0430, as well as a characteristic “dull” exhaust sound during acceleration. If you ignore the problem, the consequences can be more serious than just loss of power: melting of the catalyst honeycomb can clog the exhaust system, which will lead to engine overheating.

📊 How often do you check for errors on your Nissan Murano?
  • Only when the Check Engine light comes on
  • Once every 3–6 months
  • Before every trip
  • I never check

Pros and cons of removing catalysts: an honest analysis

Removing catalytic converters is not just a matter of “cut and forget.” Let's weigh everything real advantages And hidden cons procedures.

Pros Cons
✅ Improved acceleration dynamics (by 5–10%) due to reduced exhaust resistance. ❌ Increase in exhaust toxicity by 3–5 times (exceeding EURO-5 standards).
✅ Error disappears P0420 (with correct ECU firmware). ❌ Risk of overheating of the exhaust manifold and turbine (if there is one).
✅ Reduced fuel consumption by 0.5–1 l/100 km (subject to a working engine). ❌ Problems with passing technical inspection (inspections have become stricter since 2023).
✅ Cheaper repairs (a new catalyst costs 30–80 thousand rubles, removal costs 5–15 thousand rubles). ❌ Possible refusal of warranty service (if the car is under warranty).
✅ Reducing the weight of the exhaust system (catalysts weigh 5–7 kg). ❌ Risk of damage to lambda probes due to changed exhaust composition.

Main myth: Removing the catalysts "increases power by 20-30 hp." In fact, the increase is no more than 5–7 hp on naturally aspirated engines Murano. A greater effect is achieved only by comprehensive modification of the intake/exhaust + firmware.

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If your Murano equipped with a system EGR, removing the catalysts without turning it off can lead to even faster carbon formation in the intake manifold.

Legal implications: what does the law say in 2026?

From March 1, 2022 in Russia there are stricter inspection rules (Order of the Ministry of Economic Development No. 334). Removing catalysts now equates to "unauthorized modification of the vehicle design"which entails:

  • 🚨 Refusal to issue a diagnostic card (without it you cannot apply for compulsory motor liability insurance).
  • 📋 Fine 500 rub. at the first fixation (according to Article 12.5 of the Administrative Code).
  • 🚔 Deprivation of rights for 1–3 months in case of repeated violation (if the changes are considered dangerous).
  • 💰 Fine up to 20 thousand rubles. for driving without a valid technical inspection.

However, in practice It’s difficult to catch a violation: a visually removed catalyst is not always noticeable, and gas analyzers at traffic police posts are rare. But the risk remains - especially when passing scheduled technical inspection, where compliance with the environmental class (specified in the PTS) is checked.

⚠️ Attention: If in your PTS Murano environmental class indicated EURO-5, and after removing the catalysts the actual class drops to EURO-2, this automatically makes the machine unsuitable for use by law.

Step-by-step instructions: how to remove catalysts on a Nissan Murano?

Procedure for removing catalysts Murano includes mechanical part (cutting out or replacing with flame arresters) and software (disabling errors in the ECU). Let's consider both stages.

1. Mechanical removal

You will need:

Grinder or metal scissors

Welding machine (or clamps for seamless installation)

Flame arrestors (2 pcs. for VQ35DE)

Exhaust system sealant

Jack and supports

Safety glasses and gloves-->

Steps:

  1. Raise the car on a lift or place it on supports (working on a jack is dangerous!).
  2. Remove the heat shield (if equipped) and disconnect the lambda probes after catalysts (they can be left in place or replaced with decoys).
  3. Carefully cut the catalyst body with a grinder along the weld seam. Be careful - there may be sharp ceramic shards inside!
  4. Remove the insides of the catalyst (honeycomb) and install flame arresters. An alternative is to weld a pipe insert (but this is worse for sound and dynamics).
  5. Weld the body or secure it with clamps (less secure). Check the tightness - exhaust leaks are unacceptable!

Important: On Murano with motor VQ35DE catalysts are located directly in the exhaust manifold (so-called “collector catalysts”). Their removal requires special care, since the collector is made of brittle cast iron.

2. ECU firmware (lambda probe decoy)

After physical removal of catalysts necessarily you need:

  • 🔧 Disable the second lambda (oxygen sensor after the catalyst) programmatically or install mechanical snag.
  • 💻 Reflash the ECU for EURO-2 (if you plan to drive without catalysts all the time).
  • 📊 Reset fuel system adaptations (otherwise the engine will operate in emergency mode).

The most reliable way is chip tuning with disabling catalysts in the firmware. Cost: 8–15 thousand rubles. Alternative - installation lambda probe emulator (3-5 thousand rubles), but it is less reliable and may malfunction.

What happens if you don’t flash the ECU after removing the catalysts?

Without disabling the second lambda, the ECU will constantly record an error P0420 and put the engine into emergency mode. This will lead to:

- Increased fuel consumption (up to +2 l/100 km).

- Loss of power (ECU limits speed).

- Risk of engine overheating due to improper fuel supply.

Removal Alternatives: What to Do if Catalysts Are Clogged?

Removing catalysts is not the only solution. Let's consider legal and semi-legal alternatives:

  • 🔄 Washing catalysts: Effective only in the early stages of clogging. Special fluids are used (for example, Liqui Moly Catalytic-System Clean). Cost: 1–2 thousand rubles. Minus: helps in 30–40% of cases.
  • 🛠️ Installation of universal catalysts: Budget analogues (for example, Bosch or Walker) cost 15–25 thousand rubles. for a couple. Plus: Ecological class is maintained.
  • 🔥 Replacement with "sports" catalysts: For example, Magnum or Fabspeed with increased resource. Cost: 40–60 thousand rubles. Minus: Requires ECU tuning.
  • 🚗 Selling a car "as is": If mileage Murano has exceeded 200 thousand km, sometimes it is more profitable to sell it with faulty catalysts than to invest in repairs.

The most reliable option - installation original Nissan catalysts (item: 20060-AL50A for Murano Z50). But their price is steep: 60–80 thousand rubles. per piece. Alternative - contract catalysts from disassembly (20-30 thousand rubles), but the risk of running into the same clogged copy is high.

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If you plan to travel by Murano another 3–5 years, optimal balance of price and quality - installation of universal middle-class catalysts (for example, Eberspächer) + ECU firmware for EURO-4. This will cost 30–40 thousand rubles. and will keep the car legal.

Effect on the engine: myths and reality

One of the main fears of owners Murano - what is the removal of catalysts "will kill the engine". Let's figure out what's true and what's not.

Myth 1: “Without catalysts, the engine will wear out faster”

Actually catalysts do not protect the engine — they clean the exhaust. However, removing them may indirectly affect the life of the motor:

  • ⚠️ If you do not turn off the second lambda after removal, the ECU will pour fuel in “emergency” mode, which will lead to oil dilution and accelerated wear.
  • ⚠️ The temperature of the exhaust gases increases, which can melt the exhaust manifold (relevant for cast iron collectors VQ35DE).

Myth 2: "Removing catalysts increases oil consumption"

There is no direct connection. Oil consumption per VQ35DE depends on condition oil scraper rings And valve seals. However, if after removing the catalysts you you won't flash the ECU, the engine will run on a rich mixture, which can increase carbon deposits and bedding of rings.

Myth 3: “Without catalysts, the engine will overheat”

Catalysts don't cool engine. But removing them can lead to overheating of the exhaust tract, if:

  • You will install cheap flame arresters without thermal insulation.
  • Do not replace the exhaust manifold gasket (it may burn out due to increased temperature).
⚠️ Attention: On Nissan Murano with motor VQ35DE after removing catalysts necessarily You need to check the exhaust temperature with a pyrometer. Norm: up to 600°C at idle, up to 900°C under load. Exceeding these values ​​leads to the risk of collector melting.

Owner reviews: real experience

To get an objective picture, we analyzed reviews from owners Nissan Murano (Z50/Z51) on the forums Drive2, MuranoClub.ru and in thematic chats. Here are the key observations:

Positive feedback (70% of cases):

  • 👍 "After removing the catalysts + firmware for EURO-2 Murano I started driving faster, especially at low speeds. Consumption dropped from 14 to 12.5 l/100 km." (VQ35DE, mileage 180 thousand km)
  • 👍 "I've been driving without catalysts for 3 years - no problems. The main thing is to install high-quality flame arresters and flash the ECU." (Z51, 2008)
  • 👍 "Error P0420 disappeared, the car stopped stalling when overtaking. I go through technical inspection through friends." (VQ25DE, mileage 150 thousand km)

Negative reviews (30% of cases):

  • 👎 "After removal, oil consumption began - from 1 liter per 10 thousand km to 1 liter per 3 thousand km. Apparently, the ECU was not flashed correctly." (Z50, 2005)
  • 👎 "A strange whistle appeared on the highway after 120 km/h. It turned out that the manifold gasket had burned out." (VQ35DE, mileage 220 thousand km)
  • 👎 "I couldn't pass the technical inspection - the gas analyzer showed a 4-fold excess of CO. I had to put fakes on the lambdas." (Z51, 2010)

Conclusion: Removing catalysts Murano in most cases it gives a positive effect, but only if done correctly (high-quality flame arresters + ECU firmware). Otherwise, the risk of encountering new problems is high.

FAQ: Frequently asked questions about removing catalysts on Nissan Murano

Is it possible to drive a Nissan Murano without catalysts if you just knock out the cells, but do not flash the ECU?

Technically it's possible, but it's the most harmful option. The ECU will constantly record an error P0420 and put the engine into emergency mode with a rich fuel mixture. Consequences:

  • Increased fuel consumption (+1.5–2 l/100 km).
  • Accelerated formation of carbon deposits on valves and pistons.
  • Risk of overheating of the catalyst (if it is not completely removed) and melting of the exhaust manifold.

The maximum you can count on is 2–3 months more or less normal driving, after which problems will begin to accumulate.

How much does it cost to remove catalysts on a Murano service?

The cost depends on the region and scope of work:

Type of work Price (RUB)
Removing catalysts (cutting + flame arresters) 8 000 – 15 000
ECU firmware for EURO-2 8 000 – 15 000
Installation of lambda probe decoys 3 000 – 5 000
Replacing the exhaust manifold gasket 1 500 – 3 000

Total: the full complex will cost 20,000 – 35,000 rub. In Moscow and St. Petersburg, prices are 20–30% higher.

Which flame arresters are best for the Murano Z50/Z51?

Recommended options:

  • 🔥 MG-Race (Russia) - a budget option (3-4 thousand rubles per piece), but they last 2-3 years.
  • 🔥 Sprint (Italy) - middle price segment (5-7 thousand rubles), resource 50-80 thousand km.
  • 🔥 Magnum (USA) - premium option (10–12 thousand rubles), last 100+ thousand km, but require welding.

For Murano with motor VQ35DE optimal choice - Sprint (article SP8004). They provide good flame extinguishing and do not create excessive resistance.

Is it possible to install a 4-2-1 spider instead of catalytic converters on a Murano?

“Spider” (exhaust manifold without catalysts) can theoretically be installed, but there are some nuances:

  • ✅ Pros: improved cylinder purging, power increase by 8–12 hp.
  • ❌ Cons:
    • Required mandatory ECU firmware (otherwise there will be an error regarding lambdas).
    • Exhaust noise increases (may not pass noise standards during technical inspection).
    • On Murano With automatic transmission, jerks are possible when changing gears due to changed dynamics.

The cost of the "spider" for VQ35DE: 15,000 – 25,000 rub. + installation. We recommend only for prepared vehicles (for example, with an increased engine capacity).

How often should flame arresters be replaced after catalyst removal?

The service life of flame arresters depends on:

  • 🔧 Quality of materials: cheap steel flame arresters burn out in 20–30 thousand km, stainless steel ones last 80–100 thousand km.
  • 🛢️ Driving style: with aggressive driving (high revs), the resource is reduced by 30–40%.
  • 🔥 Exhaust temperatures: If the ECU is not flashed, the rich mixture increases the temperature of the gases, accelerating wear.

Average values:

  • Budget flame arresters: 30–50 thousand km.
  • Middle class: 60–80 thousand km.
  • Premium (stainless steel): 100–150 thousand km.

Signs of wear: increased noise, rattling, burning smell from under the car.