Po 431 i have code po431

It depends on the actual problem.
Code 431 means the catalytic converter is not performing as expected. The computer uses data from the O2 sensors to monitor cat performance.
One of the sensors may be going bad, or the cat may be failing. You would need to monitor the O2 sensor readings with a scanner and watch the temp of the cat to try to assess the problem.

Have the catalytic converter and your O2 sensor checked.

EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up (masking the original reason for converter failure).

EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up

2003 saturn vue, we dont have the engine size, the codes should be and are the same, po 128 means; cooling temp is out of spec, make sure the coolant is full, then replace the coolant emp sensor and make sure the connection is good, i would also replace the thermostant, this is a common code on these and most of the time its the coolant temp sensor or thermostant, ive learned to replace then both to avoid future engine lights with code po128. next we will check the code # po421, this code is that the computer sees that the cat converters are taking to long to warm up, code po 431 is also the same as po421, this code is related to the thermostant and sensor, the sensor give the computer the wrong temp readings and then the compuetr thinks the engine is hotter than it is and thinks the converters should be also hot like the motor but the coolant temp is giving a false reading, if you replace the coolant temp sensor and the thermostant and fill coolant , then reset the light and you will solve the problem, i hope this is helpful, also the sensor is located to the right of the engine if you are standing in front of the motor, heres a picture of the sensor, remember to check connector heres a pic of the connector, good luck.

I have about 15 years experience with Audi/VW. The coolant issue is more like the result of the ECM coolant temp sensor failure. The Cat code might be the front oxygen sensor on that bank and not the front cat. If you need more information about this repair please fell free to contact me at [email protected], I have over 30 years of automotive experience to assist you, thanks.

Its really hard to say. Some cats arnt as good as others.
A misfire can overheat a cat real easy and use up the chemicals.
If you fixed the problem then clear the code and see if it comes back. Hope for the best.

IF IT RUNS OK DONT DO ANY THING

There are 2 catalytic converters on Sedonas, it sounds like the rear one is failing. These can be replaced with generic universal ones that can be found on ebay, don't let the dealership tell you otherwise. Any number of shops would install it for you if you brought it in to them, if you don't want to install it yourself.

Despite the fact that it may be running fine right now, It sould be replaced, however. A faulty catalytic converter will result in the vehicle's computer adjusting fuel/air mixtures, timing, etc. etc. in an effort to rectify what is percieves to be an inefficient engine operation.

catalytic converter fault, I would try to replace the o2 sensor first because the cat cost just about $500! I know it is the sensor after that cat and I am pretty sure it is for the back side of the motor.

Good luck, I just replaced all o2 sensors and still got that code and I just purchased 2 cats- Big Money Problem!