**edit** Sorry, it is definately the P0420 code, not P0128. I guess you cannot edit the actual post name?

Hi guys,

I have an 2003 S40 with 130k miles. It has had the P0420 CEL code since I've had it. If I reset the code it always came back within a day.

I read about the O2 sensor spacers for the rear sensor and decided to give one a try. I'm still getting the code, although now when i reset it it takes about a week for it to come back.

Is there anything else I can check/do to try and get rid of this code? Not wanting to do anything $$$ like replacing the cat...

Also I did not buy the IPD CEL Boss, I used a cheap one from eBay. From the pictures it looks like IPD's is a bit longer than the one I have. Could that be the problem, the sensor not being pulled far enough out of the exhaust stream?

Thanks,

 

It's the cat. The spacer is a bandaid "fix" That doesn't always work.

 

I used the IPD version and it the code never came back.

 

I may break down and buy IPD's... But first I'm going to try making a little tent of thick aluminum foil with a few little holes poked in it to cover the sensor head

I realize it's just a fix to cover the real problem of a cat that is not performing 100%. But I am not prepared to spend alot money on an old car just to get the cat back up to Volvo's specs.

Thanks for the advice!

 

It's not Volvos specs, it's the government. If you're in an area that tests for emissions, you might have no choice. Modifying the emissions components is against the law too, so watch out if they do a visual inspection.

 

Yes, watch out if you have a state inspection. I live in a non-inspection state so I don't have to worry about the smog *****.

 

No worries about inspections, they stopped all that in Kentucky years ago.

 

Oh wow. I have to say Kentucky was quite insane when it came to vehicles in the mid-90's. When I moved to Louisville I first got hit with a sales tax on a 10 year old vehicle. I had to prove I paid sales tax to Florida where I bought my truck 10 years before. Then they hit me with a tax on my truck's insurance premium. And it all had to be paid at once. Next was the smog check. Holy taxes Batman. Kentucky taxed everything and often. I could not move fast enough out of that craziness.