How do I repair Code P0420

Pesky PO420 Codes - Eastern Catalytic

www.easterncatalytic.com/education/tech-tips/pesky-p0420-codes/

One of the most annoying is the persistent PO420 diagnostic code (Catalyst System ... not only shows its teeth when the catalytic converter is on the blink, but can also be ... Most, if not all, catalytic converter failures are caused by a problem or ...

P0420 Error Code: Catalyst System Efficiency Below ...

www.obd-codes.com/p0420

Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency ... If they have failed, it is likely due to something else that caused it to fail. ... the catalytic converter is broken or failed, it may be restricting the exhaust which will ...

explaining trouble codes po420 - po421 - Discount Catalytic ...

code p 420 refers to catalytic converter system bank 1--efficiency below threshold ===causes--- catalytic converter,--wiring---HO2S 2 sensor
could be a bad HO2S sensor or a failed cat converter
try the sensor first as they are cheaper than a cat

Don't have emission testing where you live ? Take the bulb out of the dash ! You illegal anyway !

P1443 is an EVAP code which means the purge control solenoid.P0401 is an EGR valve and code p0420 is a catalytic converter.

p1443 is Purge control solenoid , p0420 is catalytic converter and Egr vale for code p0401

Hi there:
The possible causes of this code are: exhaust leak between the exhaust manifold and converter, downstream O2 sensor wiring damaged due to coming in contact with exhaust pipe, or failed converter.


Check for any exhaust leaks and repair as necessary. Check wiring harness at O2 sensor and if damaged repair or replace. Keep in mind that catalytic converter have a 8yr/80,000 mile federal emissions warranty, so if you have less than 80,000 miles this will be covered undered the warranty and would need to be replaced by dealership.


We strongly recommend that if you need to replace the catalytic converter that you replace it with an OEM unit. Second choice would be a high-quality replacement part. There are many stories in our forums where folks replaced the cat with a cheaper aftermarket one only to have the code return shortly thereafter.



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the following links can assist you with causes and repair
P0420 Catalyst System Efficiency Below Threshold https://www.autocodes.com/p0420.html P0420 OBD II Trouble Code

code is P0449

The PCM has determined that a malfunction exists in the electrical circuit for the vent valve/solenoid in the evaporative emission control system.

Definition:
EVAP (Evaporative Emission System) purge/vent solenoid circuit condition

Explanation:
The solenoids and system wiring are monitored for opens or shorts

Probable Causes
1- Purge or vent solenoids defective
2- Check connevtor and wiring
3- Fuel saturated vapor canister
4- Failed EVAP vent solenoid


A code P0141 may mean that one or more of the following has happened:

• open or short to ground in the wiring harness
• O2 heater circuit wiring high resistance
• O2 heater element resistance is high
• Internal short or open in the heater element

Note: Typically a failed catalytic converter does not cause this code. You're more likely to see a P0420 code for a failed converter.
Possible Solutions

• Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)
• Repair short or open or high resistance in wiring harness or harness connectors

I would send the car for a smoke test for the emissions leak...Find out where the leak is comming from..Repair it..Reset the codes, then do a drive cycle and see what happens...

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

There is one 02 sensor in front of the catalytic converter (called upstream), and one behind it (downstream). When the engine is warmed up and running normally the upstream oxygen sensor reading fluctuates and the downstream one is fairly steady. In the case where both readings are fairly steady, a P0420 check engine light code is set.

Possible Causes:
Oxygen (O2) sensor not working correctly
Damaged or leaking exhuast (pipe, manifold, catalytic converter)
Damaged catalytic converter