Skip the auto shop - Our mechanics make house calls

P0435 OBD-II Trouble Code: Catalyst Temperature Sensor Bank 2

Check Engine Light

P0435 code definition

This Diagnostic Trouble Code (DTC) is the generic code for Catalyst Temperature Sensor Bank 2, indicating that the problem originates from the engine bank which does not contain cylinder #1.

What the P0435 code means

In order to determine proper exhaust composition and temperature, the Powertrain Control Module (PCM) analyzes data sent from the oxygen sensors, using the data to calculate catalyst efficiency. If the signal sent to the PCM by the oxygen sensors falls outside of the expected parameters, the code will set.

What causes the P0435 code?

The most likely causes of this code are a faulty catalytic converter or bad oxygen sensors. Catalytic converters can fail due to:

  • Fuel in the exhaust system
  • Improper fuel usage
  • A faulty mass airflow (MAF) sensor
  • Fuel injector malfunction
  • A faulty fuel regulator
  • A coolant temperature sensor malfunction
  • A damaged or leaking flex hose
  • Faulty spark plug timing

What are the symptoms of the P0435 code?

The signs of this problem can range from just the stored DTC and a lit Check Engine Light, to engine stalling or a no-start condition. If faulty O2 sensors or a catalytic converter operating below the optimal efficiency threshold are the issue, you will probably still be able to drive the vehicle. If the catalytic converter is broken, however, you may experience poor engine performance, hissing noises, or the inability to start the vehicle.

How does a mechanic diagnose the P0435 code?

Diagnostic procedures could include:

  • Scanning the vehicle’s computer and capturing the data, including any concurrent codes
  • Clearing the DTCs and road testing the vehicle to ensure it’s not an intermittent condition
  • Measuring the temperature of the exhaust pipe before and after the catalytic converter, using a temperature gun (preferably equipped with a laser pointer)
  • Using a scanner and oscilloscope to monitor oxygen sensor function
  • Inspecting sensor wiring and connections
  • Visually inspecting the catalytic converter

Under normal conditions, when the engine has been test driven and is allowed to idle at normal operating temperature, the upstream O2 sensor should fluctuate quickly between .350 and .900 volts. The downstream sensor should stay around .500 volts. If these reactions are slower than expected, or nonexistent, the O2 sensors could be faulty. If the downstream sensor fluctuates close to the way the upstream sensor does, it could be a bad catalytic converter.

Common mistakes when diagnosing the P0435 code

The most common error is to replace the O2 sensors before verifying that they are malfunctioning. This is often done to try to avoid replacing the (expensive) catalytic converter; however, it may not solve the problem.

Another mistake is not addressing concurrent DTCs, which if left unchecked could trigger repeated catalytic converter failure.

How serious is the P0435 code?

The severity of this issue really depends upon the source of the problem. Catalytic converter failure may eventually affect engine performance, causing further damage. It can also cause problems with emissions testing if this is required in your state.

What repairs can fix the P0435 code?

Potential repairs include:

Additional comments for consideration regarding the P0435 code

It’s always advisable to diagnose and repair any other DTCs present along with the current issue, but it’s especially important in this case. There may be other O2 sensor, fuel mixture, fuel trim, or misfire codes and these should be addressed before assuming the repair is complete.

Due to the fact that the vehicle will likely need to be lifted in order to diagnose and repair P0435, your best bet is to have your car checked by a qualified technician who has the tools, equipment, and expertise to efficiently identify the problem and get you back on the road.

Need help with a P0435 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...


Related questions

Q: my 2008 yukon was in two accidents in 30 min. i now have codes popping up i have had a check tire monitir system, air suspension a

It sounds as though the trouble codes are probably a result of the accidents. With no warnings prior to them, and now having them on, I can only assume that this was the cause. But, it would be necessary to...

Q: What does the Service Engine Soon Light mean on the dash?

The Service Engine Soon Light is tied into your car’s Emissions system, which includes a broad range of sensors and components in the engine, your Fuel system, and the Emissions system. When you first crank the car, the Service...

Q: eva PO597 engined coolant thermostat heater control circuit from obd diagnostic tool

Hi there. For the code P0597 to appear, there is an issue with the engine cooling system. Check the harness to the thermostat housing and a good connection and make sure that there is corrosion. Check for any coolant leaks...