My car failed inspection with P0420 and P0411 codes 2005 VW Jetta

What does that mean and what needs to be done to correct these issues so that my car can pass inspection?

My car has 100000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi there – the P0420 indicates a catalytic converter that is not working as efficiently as it should. This could mean a clogged converter, or weak oxygen sensor (probably the pre-converter O2 sensor). The P0411 code indicates a secondary air injection pump "low flow" problem. This pump injects air into the exhaust to complete combustion of unburned fuel. The message indicates the pump is not providing the expected amount of air. This could be due to a weak or worn pump, or clogged air filter for the pump. I would recommend an exhaust and emissions inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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Code P0420 indicates that the catalytic converter is not functioning efficiently, therefore increasing the output of harmful pollutants by the vehicle.
Hi there – the P0420 indicates a catalytic converter that is not working as efficiently as it should. This could mean a clogged converter, or weak oxygen sensor (probably the pre-converter O2 sensor). The P0411 code indicates a secondary air injection pump “low flow” problem.
The P0420 code signals a low catalyst system efficiency. This code suggests that the oxygen levels are below the desired threshold (Bank 1), which most often results from problems with your car`s exhaust or fuel systems.
The code P0420 can be caused by the catalyst, O2 sensors before and after the catalyst. If both O2 sensors and catalyst was replaced then you may have an exhaust leak at the manifold or pipes.
A P0420 code is set when the upstream sensor and the downstream oxygen sensor sense the catalytic converter is not doing its job. Basically, the amount of oxygen going into the converter is not being burned, and it detects it through the downstream sensor.
Possible Fixes

When the P0411 code is set, it means that the PCM doesn`t detect an appropriate drop in the voltage from the O2 sensor, which would indicate air being injected into the exhaust stream. The problem isn`t necessarily the pump itself, though, so other components in the system should be checked first.

The p0420 code means that the catalytic converter is below threshold and is not functioning correctly. This code comes up when the catalytic converter can no longer burn off any fuel in the exhaust system.
Can you drive with the p0420 code? In the short term, driving with a P0420 code is usually fine. The driver is not at risk because of it. This code can harm your engine and exhaust system if you drive for an extended period of time.
Simply put, a P0420 code means that the catalyst system efficiency of your car is below threshold (Bank 1). The P0420 error number indicates a low catalyst system efficiency. This is usually caused by issues with your vehicle`s exhaust or fuel systems. It can be difficult to diagnose at times.
But not always. it could be caused by an exhaust leak in or around the converter. Or, it could be related to a faulty A/F Sensor (front oxygen sensor).
A common emissions code seen in the field, a P0420 trouble code indicates that the catalytic converter isn`t functioning efficiently.
The most common mistake is replacing the oxygen sensors before completing the diagnostic process. If another component is causing the P0420 trouble code, replacing the oxygen sensors will not fix the problem.
Most catalytic converter failures fall under one of three categories: Overheated, melted or broken converters.
While O2 sensors will have a natural lifespan, there are a few things that can cause them to fail more quickly. Contaminated or dirty fuel injectors, engines that burn oil, and even a very dirty air filter can cause O2 sensors to become faulty.
The MAF sensor malfunctioning can also cause your car to throw a check engine light (CEL). Furthermore, it can cause different check engine codes such as the O2 sensor, “low air volume”, or something else.
One of the most common reasons is that you simply may have a faulty O2 sensor that needs replacing. If an O2 sensor receives too high of voltage, or experiences corrosion around the sensor connector, this can very easily damage the sensor and cause any of these codes to appear.
P0131 O2 Sensor Low Voltage Bank 1 Sensor 1 — What It Means

In this instance, Bank 1 Sensor 1 would mean the sensor closest to the manifold, on the driver`s side cylinder bank of a V6 or V8 engine. The signal from the O2 sensor is used to determine fuel metering and ignition timing.

Oxygen sensor bank 1 sensor 1 is also known as upstream oxygen sensor or lambda sensor 1. This oxygen sensor is located before the catalytic converter and it is very important for the normal operation of your engine.
Start vehicle engine. If the power supply of the secondary air pump is fine, but the secondary air pump runs with a scraping, whistling or scratching noise or not at all, the secondary air pump is to be replaced. Check electrical contacts of voltage supply to secondary air pump.
Engine Stall

The failed secondary air injection pump can cause fluctuation in power. For instance, in one minute your vehicle is performing well and in the other minute, you may face a drop in revs. Thus, you need to replace the pump to avoid continuous engine stalls and ensure a smooth drive.

If the engine is burning oil, which sounds like yours does, this can damage the catalytic converter, which can result in the P0420 DTC.
Repair Urgency: Get this code fixed as soon as possible to avoid further damage to your emission system and possible engine damage. Diagnosis: The most common cause of P0420 is a bad catalytic converter, but it can be caused by anything from a faulty oxygen sensor to a rich or lean running condition, or misfires.
This discrepancy can be caused by various things, such as a malfunctioning catalytic converter, a clogged air filter, a vacuum leak, or an issue with the fuel system.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car failed inspection with P0420 and P0411 codes 2005 VW Jetta
ANSWER : Hi there – the P0420 indicates a catalytic converter that is not working as efficiently as it should. This could mean a clogged converter, or weak oxygen sensor (probably the pre-converter O2 sensor). The P0411 code indicates a secondary air injection pump "low flow" problem. This pump injects air into the exhaust to complete combustion of unburned fuel. The message indicates the pump is not providing the expected amount of air. This could be due to a weak or worn pump, or clogged air filter for the pump. I would recommend an exhaust and emissions inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

Can i retrieve CEL code from car … forgot what code it hade in my car .. put headgasket sealer and i erase the code ..
ANSWER : Once a trouble code is erased, it cannot be retrieved. The engine controller does not have a "recycle bin" like they have on Windows. If the car still has a problem, the code will come back up after some driving. However, the controller will not turn on the CEL until it has seen the malfunction on two separate "trips." A "trip" is a driving cycle where the car is started cold, driven until it is fully warm and through a certain number of accelerations, and shut down. So you might not see the CEL for a couple of days. As for the "head gasket sealer," I wouldn’t hold out too much hope of that solving a problem. At the very best it might put off the symptoms for a short while. If you need help interpreting codes that come up, or solving a head gasket issue, contact Your Mechanic. They can send a technician to your home or office to read the codes on your car and help you decide what to do.

Will the P0597 code cause the car to fail emissions inspection in North Carolina?
ANSWER : Hi there. The code P0597 is for the thermostat heater control circuit. This means that the thermostat is electronically controlled in your vehicle. To see why this code is on, check the following:

A loose or corroded connector on the thermostat
A coolant leak in the cooling system – make sure that all connections are tight
The thermostat could have failed – stuck open or partially open
There could be a short in the wiring harness between the computer and thermostat
The ECM (computer) has failed – Only in the event that all areas have been check and are all functional

Once the engine light is off and the engine is running correctly, you would be able to retest your vehicle at the emissions in your state. If you need further assistance with your check engine light on, then seek out a professional, such as one from Your Mechanic, to help you.

I put the wrong key in my car and a few weeks later my car just shut down and it will not start I believe it’s the computer but…
ANSWER : Hi there. What had happened is the wrong key set the security to the vehicle. This is to prevent the vehicle from starting with the wrong keys. Try removing the battery cables (+) and (-) for 13 minutes. During that time, put the original key in the ignition and turn it on. Activate everything in the car even though there is no power. Then remove the key and hook up the battery cables. The computer should have reset and reset the security. If the security is still being tripped, then I recommend seeking out a professional, such as one from Your Mechanic, to help you

Replaced alternator on car 2 times each time shows it’s charging 14v let car run for a little bit then test drive and car voltage
ANSWER : There are reports that the replacement alternators will not communicate with the engine computer and will not charge correctly. I recommend using only the manufacturer approved replacement part. It can be new or remanufactured but approved for use in the vehicle. Some lower cost alternators on the aftermarket will have charging problems since they will not communicate with the ECM on the vehicle and will stop charging.

Why does the emission inspection failed almost every time its due for DMV inspection?
ANSWER : Hi there:

Honestly, the lack of consistent driving could be the reason why you have frequent emissions issues. If the car does not run frequently and have an opportunity to circulate built up carbon deposits on the inside of the fuel injection system or exhaust system, failed emissions testing may be the result. The best thing to do is to drive your vehicle once or twice per week about a month or so before your emissions testing is needed. Also, it’s a good idea to replace air filters frequently before emissions testing is completed. This article is a good one that helps many car owners learn what they can do to help improve emissions testing.

2004 Nissan Altima- Won’t move when the code reads p0420 on the scanner. Did my transmission go? Is it my catalytic converter like code said?
ANSWER : Hi there. The code P0420 means that the catalytic converter is below threshold and cannot burn off any emissions in the exhaust stream. The O2 sensors have pickup this fault and put the engine into limp mode. As for the vehicle not moving, the exhaust may be plugged up causing the engine to not breathe properly. Put the vehicle in drive and set the parking brake. Fully step on the gas pedal to the floor and have someone feel the exhaust pipe. If there is very little pressure coming out of the pipe, then the catalytic converter has plugged up and needs replaced. If the pressure is normal, then the computer may have locked the transmission out of the drive cycle. If you need further assistance with your vehicle not moving due to the code p0420, then seek out a professional, such as one from Your Mechanic, to help you.

Can my car be driven safely on a limited basis with the car diagnostic codes listed below in the description?
ANSWER : All of these codes (P0121, P0638, P2106, and P2110) point specifically to problems with the throttle control systems. This means that it will be unsafe to drive at all until it is diagnosed properly and repaired. You may need a new throttle body assembly. I absolutely do not recommend driving it.

If you need assistance with getting this fixed, consider contacting a certified technician who has the necessary tools and experience to properly diagnose your trouble codes. Once this is done, an accurate repair can be made and your car will be suitable for the road once again.