P0430 and P0420

P0430 and P0420

What are P0430 and P0420 DTC,s 

These code are set by the ECM when it detects that the substrate of the catalytic converter has totally decayed and it is not absorbing the harmful gases (if any). This code can cause the car to operate in a limp mode and slow down the overall performance. New research on the P0420 and P0430 code suggests that the limp mode or restricted mode may cause more harm to the environment than doing any good and engines must only rely on the primary oxygen sensor. Please note that disabling this sensor may not cause any harmful effects if the Air fuel ratio remains in the set limit. Manufacturers follow a range threshold for the oxygen sensors to operate on, any deviation will set the DTC.

Because they contain rare earth minerals like palladium, gold and platinum, new catalytic converters are expensive. You can bring the car to us and we will adjust the AFR according to fuel available in Pakistan.

poor oxygen sensor

Oxygen Sensors ?

Some popular part no,s of Toyota oxygen sensors are








How oxygen sensors operate ?

The engine control unit (ECM) monitors the switching frequency ratio for heated oxygen sensors 1 (O2 front sensor) and heated oxygen sensors 2 (O2 rear sensor). A three-way catalytic converter with a high oxygen storage capacity will indicate a low switching frequency for heated oxygen sensor 2.

If the oxygen storage capacity drops, the switching frequency of the second sensor will increase. When the ratio of the frequency of the heated oxygen sensors 1 and 2 approaches the specified limit set by the manufacturer, The P0430 DTC will be stored in the ECM. This can be caused due to a clogged catalytic converter. However if the catalytic converter is cleaned than a faulty oxygen sensor can be one reason. it is recommended to have the waveform properly diagnosed to ascertain the problem area. This requires a high skill and experience. fixmycar.pk has the expertise to adjust the limit values of the oxygen sensor and bring the combustion process back to its factory value.


P0430 TOYOTA – Catalyst System Efficiency Below Threshold Bank 2

As this code directs to a faulty 3 way catalytic system specially in a 1UR Landcruiser V8.  Some of them can be due to poor inlet system or even a faulty ECM. The code can also be triggered by a leaking injector. We have also seen some cars with a leaking inlet system causing this code, we recommend that you get the car properly inspected at our garage in Islamabad for a proper diagnostics. We have successfully cleared many cars of this error by increasing the threshold vales / waveforms. This brings the cars power back to normal.

Replacing the oxygen (O2) sensors may sometimes fix the code. Mostly catalytic converters require replacement to fix the problem. If the P0430 and P0420 code is combined with other codes, then all of them need to be cleared first. In some rare events even a faulty ECM can cause this code to come up.

Poor acceleration due to P0430 and P0420

The function of the catalytic converter is to break down harmful pollutants that get created in your vehicle. The combustion cycle converts them into less harmful gases. Code P0430 and P0420 indicates that the catalytic converter is not functioning properly, therefore increasing the output of harmful pollutants by the vehicle. Any compromise with the fuel delivery system can cause poor accleration. When the converter is not functioning properly, the output of toxic gasses also increases.

V6/V8/V12 Cylinder Engine with 2 Exhaust banks and 4 Catalysts

Engines with V type configuration have almost 4 to 6 oxygen sensors, this is based on the area of vehicle it is designed for by taking the EPA rating in consideration, however a lot of debate is going on the subject that the catalytic converts cause more harm than good once they go bad. A lot of manufacturers are now considering making the engines efficient enough not to rely on the catalytic converter itself.

Most V8 engines like the 1UR with following specification follow this configuration for arrangement of catalytic system in the exhaust system.

1UR torque and HP




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