Volvo still may have the CAT. Need your Year, engine type, VIN to know the exact one.
Use Online Volvo Parts Superstore | OEM Parts Online To search the part number(s).
Another option is Midas muffler type shops to weld in a replacement the CAT.
We have sent customers to muffler shops with good luck for CAT replacement.
Especially if the car has lived in snow, road salt areas and everything is very rusted.
Another option is to search for and install an 02 spacer in the rear 02 sensor.
The code sets because the CAT becomes slow/lazy. It still works or it would set more serious codes.
02 sensor threads are 18mmX1.5 Same thread as the engine drain plug.

Online Volvo Parts Superstore | OEM Parts Online

 

Thanks - I double checked the link you provided and the original cat is indeed discontinued for her car. :-(

I would love to try an O2 spacer just to see if the light goes away (Car drives fine, plenty of power) but the rear O2 is impossible to get to on this car. It points up towards the floor, and is located on top of the cat. I had to farm the job out to a local shop to replace the old rear O2.

 

Thanks - I double checked the link you provided and the original cat is indeed discontinued for her car. :-(

I would love to try an O2 spacer just to see if the light goes away (Car drives fine, plenty of power) but the rear O2 is impossible to get to on this car. It points up towards the floor, and is located on top of the cat. I had to farm the job out to a local shop to replace the old rear O2.

not impossible, they favored the sensor to one side so you can put a stubby sensor socket on it and 3/8 breaker bar, torch the sensor mount to cherry red and it will come out a lot easier.

Amazon.com: TEKTON 3/8 Inch Drive x 7/8 Inch Offset 6-Point Oxygen Sensor Socket | 47749, Original Version : Everything Else

Amazon.com: TEKTON 3/8 Inch Drive x 7/8 Inch Offset 6-Point Oxygen Sensor Socket | 47749, Original Version : Everything Else

www.amazon.com

 

Replace both oxygen sensors. They are good for 100-150k miles max.

In any case, don't throw away your cat, it is metallic, top notch. Instead pay a welder to transfer the cat to a new downpipe.

 

In any case, don't throw away your cat, it is metallic, top notch. Instead pay a welder to transfer the cat to a new downpipe.

Cats can burn out and lose ability to do their job after a while though. I removed my stock cat from my 2000 XC at around 270K miles (19 years), wasn't clogged or anything. I took it to a salvage place to sell, got a couple hundred bucks for it. They said it would have been worth more because it's a very high quality cat (like you said), but they examined it inside and saw about half the catalyst material was burned away, just from use over the years.

I agree though to try and troubleshoot all other options before a cat replacement, mainly due to the cost. O2 sensors can definitley trigger stuff like that.

 

OEM cats don't burn out easily. If you are getting a code for the downstream O2 sensor the first step should be to get the injectors cleaned or swap for a freshly cleaned set. If you have a code for the forward oxygen sensor replace that with OE.

 

Just replace both if they are still original. Front sensor will return both a better MPG and more oomph.

https://images.oreillyauto.com/parts/img/documents/bos/catalog_oxygen_sensors.pdf 17137 (front) - 100k miles, 16488 (rear) - 100k miles, too.

 

i would check fuel trims first.

 

Both O2 sensors replaced within the last few years with OEM.

230k miles. New fuel pump, fuel pressure sensor. I've gone through the engine bay and checked vacuum lines and got pretty deep into it when doing the timing belt/WP last summer. No exhaust leaks. It has had the ECM-4801 catalytic converter efficiency code for many, many years. I've done my best to research it over the years, and the only thing left is injectors, but at this point her budget is either for a new cat, or injectors - not both.

Unless we can reset the code and pass NY inspection again next month... which has worked (somehow) for a long time.

 

Can't find a muffler shop to cut the old one out and weld in a generic one? Should be 1/2 to 2/3 the cost of the performance pipe, though getting back the power the car has lost over the years would be a no brainer for me!

 

Daughters 2004 P2 had a catalytic converter code for years. Replaced the injectors and problem solved.

 

Can't find a muffler shop to cut the old one out and weld in a generic one? Should be 1/2 to 2/3 the cost of the performance pipe, though getting back the power the car has lost over the years would be a no brainer for me!

Haven't checked yet though I suppose that would be cheaper than the IPD performance DP if we end up going that route!

Daughters 2004 P2 had a catalytic converter code for years. Replaced the injectors and problem solved.

Looks like a set of new Bosch injectors is about $200. I guess I can just buy them for her and try it out. The logic behind this is beyond me but it wouldn't be the first time I've seen injectors as a potential fix.

 

Haven't checked yet though I suppose that would be cheaper than the IPD performance DP if we end up going that route!



Looks like a set of new Bosch injectors is about $200. I guess I can just buy them for her and try it out. The logic behind this is beyond me but it wouldn't be the first time I've seen injectors as a potential fix.

Shouldn't injector codes be thrown? Maybe too advanced for P2. Seems running rich, for example, could consume the cat. Have you tried injector clean?

 

The injectors clog up after a while. Then their flow rates differ. Engine computer aims for a mixture as defined by the upstream O2 detector but some cylinders are getting more fuel some less. Those rich (or very lean) pulses are more difficult for the catalyst to digest and eventually sets off the code for the rear O2 sensor. You can fool the rear O2 sensor by mounting it to a 90 degree fiting, but that is technically illegal (it creates a stagnation zone).

I didn;t believe it either until I read it on here and decided to try it (remanufactured in my case ran 85 at the time). You could also run an in tank fuel injector cleaner with PEA in it (Redline, Chevron) but it might take a lot to clean. Or buy injector rebuild kits and one of those cheap fuel injector cleaners, pull the injectors, use a screw to remove the baskets, hook it up to the ebay thing and pipe in your favorite aerosol carb cleaner while hooking a battery to open the injector, then replace the o-rings. Those cheap ebay cleaner kits leak after one set of injectors, and there is a bit of fire risk so just easier to buy remans.

 

Grab a set of used injectors and send them out to be cleaned/rebuilt. I sent in a set of blue injectors with just over 100k on them. No flow issues. They are like new now. Cost about $80 a couple of years ago.

 

If the car is AWD, this is what I have in my XC70 and it’s fantastic quality and a great price. It is worth noting that the cat isn’t the most efficient so it pops a check engine light up once every 5k miles or so, but I just clear it.

https://re-volvparts.com/store/home/93-re-volv-3-stainless-race-downpipe-for-p2-awd-cars.html

I’d also look into exhaust shops that can weld in a replacement cat if the exhaust isn’t very rusty

 

If the car is AWD, this is what I have in my XC70 and it’s fantastic quality and a great price. It is worth noting that the cat isn’t the most efficient so it pops a check engine light up once every 5k miles or so, but I just clear it.

https://re-volvparts.com/store/home/93-re-volv-3-stainless-race-downpipe-for-p2-awd-cars.html

I’d also look into exhaust shops that can weld in a replacement cat if the exhaust isn’t very rusty

looks slick, the parts store want $900+ for that downpipe.
I made a wooden jig and welded a new flex pipe instead.
no more codes so its all good for now.