2003 S40 Rear Cat Converter

supertuner · Post by **supertuner** » 18 Nov 2011, 10:02

This is my initial post, I was a red light and went to accelerate then, went over a hump in the road that I didn't notice and then, bam, the car just got a really throaty, loud sound. so I pulled over and look under to see exhaust leaking from the rear cat at the portion where the steel mesh is. So what my question is how difficult is it to replace the entire rear cat assembly. I called a dealer and got a price for the rear cat part (866.26) plus about $10 for the gaskets. I was looking online and found some between 220-550 (Davico, Benchmark, Magnaflow). So is it worth buying dealer direct, should I have them install at a rate of about $110 I can really save some cash doing it myself if manageable. It seems pretty straightforward from some research I have done just bolt on with the rear from what I grasp. If any of you have advice I would appreciate it. Also is there anything else I have to replace when doing the rear cat; the service guy mentioned a gasket, but is it worth new bolts as well if there rusted badly, any sensors I would have to replace?

Post by **Choguy03** » 18 Nov 2011, 11:17

New studs wouldn't hurt. I had to grind one off and put a bolt through it. The gasket just helps prevent leaks, so you should replace it too. It is a really easy job. Buy the part and do it yourself. I am not sure that you will need to replace the O2 sensors. As long as you get them out, you should be fine. Put some anti-seize on them when they go back in to help later down the road if you need too. Also, you may be able to get a muffler place to just weld a new piece on there to cover the hole. I don't know if it is possible, but it is cheaper then the $300 for parts. Here you go:

supertuner · Post by **supertuner** » 18 Nov 2011, 11:40

Thanks for the diagram, I thought it looked pretty straight forward, do you recommend any particular replacement brands or vendors

Post by **Choguy03** » 18 Nov 2011, 12:11

I haven't had to replace one, so I have no preference there. Maybe somebody will drop by and share some input. Keep us posted and take some pics.

Sent from my BlackBerry 9810 using Tapatalk

supertuner · Post by **supertuner** » 18 Nov 2011, 19:42

Thanks for the diagram, I thought it looked pretty straight forward, do you recommend any particular replacement brands or vendors

supertuner · Post by **supertuner** » 18 Nov 2011, 19:55

does anyone know if the original cat is stailess steel I was looking at one unit from davico mfg that just says it steel, and other manufactureres state stanless converter case and/or aluminized pipe. would this be vital or do you think I could go with the davico one?

supertuner · Post by **supertuner** » 21 Nov 2011, 06:42

I ordered a new one online but now I just I have to get new hardware for it, The original are rotted through. should I get some from volvo again or just replace it with Stainless Bolts from the hardware store?

Post by **Choguy03** » 21 Nov 2011, 06:49

Either way will work. Volvo is going to be more expensive, but maybe easier since you will get the correct parts the first time.