P0422

[GearheadTool]

Well, I mentioned this in the "running" thread, for MY car.. But, since this is the Mech/Maint forum, let's hear about some thoughts/experiences with a P0422 code on YOUR car, or other cars, besides this **** Volvo.

Just saw a P0422 code flash across my OBDII; so.. educate me about why that could happen (general conditions..) Thanks!

 

[bigjl]

You have the code reader. What does it say the code indicates?

 

[GearheadTool]

Originally Posted By: bigjl
You have the code reader. What does it say the code indicates?


I had to Google it, but it seems to be indicating something about the Catalytic converter..

http://www.obd-codes.com/p0422

P0422 Main Catalyst Efficiency Below Threshold (Bank 1)

OBD-II Trouble Code Technical Description
Article by

Dale Toalston
ASE Certified Technician

Main Catalyst Efficiency Below Threshold (Bank 1)
What does that mean?

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

Symptoms of a P0422 DTC may include:

Increased tailpipe emissions
MIL (Malfunction Indicator Lamp) illumination

Causes

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.

Layman's observation: I noticed that sometimes, a car will turn the light on when sitting and exhaust gasses "back up" somehow. I cleared the code, and will check out if it comes back.

 

[asiancivicmaniac]

You need a new cat converter

 

[JamesBond]

Putting fuel additives in your tank can make this code pop up. Stick to gas only for the next few months and it will probably go away.

DO NOT TOUCH the catalytic converter, DO NOT REPLACE the catalytic converter, DO NOT ADD more stuff to the tank in an effort to resolve this code.

 

[asiancivicmaniac]

It's easy to tell if your cat converter is gone. If you smell sulfur then it's most likely toast.

 

[surfstar]

 

[JHZR2]

COuld be a bad O2 sensor too, which Id swap before putting in new catalysts, especially on an older car with questionable history.

But no way Id do any of that before getting the timing belt fixed!

 

[JTK]

Originally Posted By: asiancivicmaniac
It's easy to tell if your cat converter is gone. If you smell sulfur then it's most likely toast.


Rotten egg stink indicates the vehicle is running too rich, not that the CCs are bad.

Assuming the P0420 code is on the 13yr/old Volvo, the CCs are probably worn out. I know I'd do the spark plug anti-fouler trick to the downstream O2 sensor on that bank before I pursued anything else.

Joel

 

[Quattro Pete]

Originally Posted By: JTK
Originally Posted By: asiancivicmaniac
It's easy to tell if your cat converter is gone. If you smell sulfur then it's most likely toast.


Rotten egg stink indicates the vehicle is running too rich, not that the CCs are bad.

Joel

Even though our gas is not ultra low sulfur, it is much lower sulfur than it was just some 10 years back. You're unlikely to smell sulfur even if the engine is running a bit rich.

 

[scurvy]

What it really means is your searching skills are sub-par at best.

I know you asked for P0422 advice on vehicles in general, but I was able to find specific fixes for the turd you continue to polish in a few seconds.

Once upon my departed OBD-I Volvo, I had a similar code pop up through the morse code reader under the hood. The accordion tube after the airbox and MAF had some splits along the ribs and it was letting in unmetered air. 10 minutes with a roll of black Gorilla Glue tape and my pocketknife, I had all the splits covered & reinforced. Code went away after that and the car ran happily for a few more years until I traded it.

But I also did the timing belt and all other maintenance on schedule.

 

[JTK]

Originally Posted By: Quattro Pete

Even though our gas is not ultra low sulfur, it is much lower sulfur than it was just some 10 years back. You're unlikely to smell sulfur even if the engine is running a bit rich.


Agreed, but AFAIK, this smell is still not an indication of a failing CC.

Joel

 

[bubbajoe_2112]

Unless you've done anything to "poison" the cat, really doubt it's a bad cat at only 134K miles.

My bet would be a bad connection or bad post-cat O2 sensor.

And Bank 1 is the bank with cylinder #1...

 

[eljefino]

When's your inspection? April? Fix it in April.

 

[cptbarkey]

in other news, John McAfee is close to returning to the united states. Belize is out of luck.

 

[KrisZ]

Why not take a bunch of pictures, make a video and tell us what elixir you're gonna run since you won't listen to any level headed advice here and spare the drama?

What was the point of that running thread again?

 

[PF52]

I read somewhere that code can pop up due to issues with the timing belt stretching or when its about to break.

 

[G-MAN]

Originally Posted By: css9450
I read somewhere that code can pop up due to issues with the timing belt stretching or when its about to break.

 

[yonyon]

Originally Posted By: css9450
I read somewhere that code can pop up due to issues with the timing belt stretching or when its about to break.


Again, I'm no Volvo guy, but for at least some other cars it's possible to get a cat eficiency code from a stretched timing belt. Obviously, normal causes such as catalyst failure, missing heat shields, and intake and exhaust leaks should always be eliminated before looking in that direction.

A stretched timing belt will retard the cams and depending on the trigger can also retard the ignition. This leaves more unburned air/fuel in a richer ratio entering the cat and gives it more work to do. A cat that would otherwise be good enough fails to do the job; the cat isn't faulty but isn't working well enough either.

 

[GMBoy]

Just replaced a cat for a friend on a 2004 CTS 3.6 with 189k miles. The first time the code popped, we cleared it, ran some redline cleaner and hoped for the best. It came back about 500 miles later. The GM service manual specifically says NOT to replace the o2 sensor unless that code was also set. She only had the cat code so on when a new cat converter and light has been off for last 2500 miles or so.

BTW - we used a Davico direct fit convertor for $145 shipped...LOTS cheaper than dealer and better than a universal fit one.

So --- to the poster -- you may be able to buy some time, but you will need to get a converter now or very soon.