Volvo Enthusiasts,

In the past month, I've been clearing this P0422 code on a 2000 S70. The vehicle is running very well. Should I take the S70 to be looked at??? I'm planning on taking a road trip, should I be concerned?

 

I would have it checked to be sure. That code leaks to a bad Cat converter.

 

Is there a way to test for a bad cat? I'd hate to purchase a new cat and have the code re-appear.

What do you check out for this code?

 

There is really no test to test the cat.

 

replace rear o2 sensor or read the following belowfrom a previous post, not mine)

I have been chasing a P0422 on my 2000 XC70 (140K miles) for a few months.

I may have finally resolved it in the past week.

It was an obtuse, but inexpensive problem to fix.

My approach was to eliminate all the places where un-metered air could get into the intake manifold.... clean and clamp the vacuum hoses; etc.

After checking and rechecking everything, and making some significant improvements in the performance and economy along the way, I still got an occasional P0422 under specific driving conditions.

One more check last week and I discovered that one of the two plastic clips on the intake air temperature sensor was broken off.

I bought a new one from volvo for about $20. It took 2 minutes to replace.

With only one plastic clip, the sensor will work fine at highway speed and a good vacuum in the intake. At suburban driving, the seal is not so good, and a positive pressure in the intake (like when you let you foot off the gas), might even push the sensor partially out.

IMHO, the only way that sensor got broken was when it was in the dealer for service. From the looks of the break, it has been broken for a while.

I think that this solution to P0422 would more likely apply to turbo vehicles, as the non-turbo's would not have the positive pressure in the intake.

Good luck !

 

The rear 02 sensor is the one that will throw the code leading to a possible cat replacement

 

po422 (threewat cat converter efficiency)
possible causes are missfires/ leak in intake system/ leak in exhaust system/ faultyfuel pressure/defective cat.
you should begin with leaks first . when was the last time you replaced your fuel filter ect...