I have a 2001 hyundai elantra and its shooting codes p0422 and p0302 i keep seeing 422 is the cat but is 302 related in anyway or could it be bad sensors anything that can save me from having to repla

Hi there:

DTC P0422 Main Catalyst Efficiency Below Threshold (Bank 1)
A vehicles' catalytic converter (catalyst) helps improve tailpipe emissions by oxygenating the exhaust gasses. It helps convert hydrocarbons (HC), Carbon Monoxide (CO), and oxides of Nitrogen (NOx) into water vapor (H20), Carbon Dioxide (CO2), and Nitrogen (N).



The PCM (Powertrain control module) monitors the catalyst efficiency by means of a post-catalyst Oxygen sensor. This sensor is used primarily for this purpose. It should switch much slower than the front oxygen sensors. If at any point the PCM detects that the post-catalyst o2 sensor is switching too rapidly (indicating no change between the inlet and outlet of the catalytic converter) it interprets this as a catalyst that isn't functioning properly.


Bank 2 is the side of the engine that has cylinder #1.


Symptoms of a P0422 DTC may include:
Increased tailpipe emissions
MIL (Malfunction Indicator Lamp) illumination

Potential causes of a P0422 code include:
Bad or non-functional catalyst
Engine operating out of optimal air:fuel ratio


Possible Solutions: Catalytic converters contain precious metals like platinum, palladium, rhodium among others. Basically, the cheaper the cat, the less precious metals used. It should be noted that there are some automobile makes that are very finicky when it comes to catalytic converters and the logic that the PCM uses to monitor them. Just because the parts guy says it will work doesn't mean that it will. The reason is that the engineering of the vehicle was done with a high quality catalyst in mind and it can't be replaced with a low cost catalyst. There are also different kinds of catalysts. Some makes will allow for a cheaper catalyst while others simply will not. Toyotas & Subarus are the most notorious for this. Subarus require CARB certified catalysts to keep the check engine light off and won't tolerate an aftermarket catalyst, no matter how expensive.


So basically if you have a recurrence of this code after replacing the catalyst with an aftermarket catalyst, this may be your problem. If you have this code and haven't replaced the cat, there's basically two likely causes: The catalyst is no good, or the engine is running out of optimal air:fuel ratio. A tune up or engine repair may correct it. Otherwise you'll need to replace the catalyst.


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We just had a e test and passed and that code just came up two days later, so don't bet the farm on a bad catalyst converter !

Hi there:A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

For example, a P0302 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #2; same condition in P0301 - cyl #1, P0303 - cyl #3 and P0304 - cyl #4.

A code P0300 (or 301, 302, 303 or 304) may mean that one or more of the following has happened:
Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Defective computer

About your possible solutions, if there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.


Hope this helps.

you have a 2001, catalict converters are guaranteed for 20-30 years. Your code respresents a problem with your Co2 sensor, probably needs to be replaced or cleaned out real good

what can i do to fix the output speed sensor

this means your catalytic converter is no longer doing wut it supposed to! needs replaceing ! u can drive the car! but get it done asap

P0422 - Catalyst below threshold.

Catalytic converter is clogged or out of medium.

Replace it.


ACTUAL DIAGNOSTIC:

Fault Code Definition
Code P0422 indicates that the Bank 1 Main Catalytic Converter's emissions efficiency has fallen below the minimum allowable limit. This threshold is tracked by a Catalyst Monitoring Oxygen Sensor located on or near the outlet of the Catalytic Converter.

Symptoms

* Check Engine Light will illuminate
* In many cases, no abnormal symptoms may be noticed

Common Problems That Trigger the P0422 Code

* Defective Catalytic Converter
* Engine misfires have damaged the Catalytic Converter
* Internal engine damage resulting in high oil consumption and/or a leaking Head gasket has damaged the Catalytic Converter

Common Misdiagnoses

* Oxygen Sensors are replaced when the real problem is a damaged Catalyst
* Catalyst is replaced when the real problem is internal engine damage, which is producing elevated emissions levels
* Catalyst is replaced when a misfiring engine is the real problem



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P0302-Cylinder 2 Misfire Detected How do I track down the problem and fix?

P0422 does not refer directly to an O2 sensor. That is a different code. P0422 is about the CAT. How many miles you have it and when did you buy it? VW has extended a warranty on the New Beetles for the CAT to 120,000 mi and 10 yrs. I had the same code and took it to the dealer to see if they'd replace the CAT in the warranty and they did. I had 47,000 miles and bought it at the end of Aug 1999, so I just slipped through. They replaced the downstream O2 sensor as well - all free of charge!

P0133 is an oxygen sensor "response too slow" code (meaning it's not getting up to temperature quickly enough, and the computer is assuming damage to its heating element). P0422 is a catalytic converter problem indication (cat is below peak efficiency). It's assuming you have a failure with the primary O2 sensor and that the cat is also bad. Change your O2 sensor first, have the codes cleared, and see if the cat code comes back or if the O2 sensor change fixes both issues.