I have a 2001 xc70 with 107k miles on it. It seems like every six months I'm dropping $600-$800 on it. Recently the 'transmission service required' light and the 'check engine' light came on. I brought it into the dealer and they said everything checked out ok, except there was an issue with my catalytic converter, that wasn't pressing. On the drive home the check engine light came back on. I brought it back and they said it now was a permanent failure code ECM 4801. And the cost to replace the catalytice converter, midpipe, and muffler was $1780. Ouch. My questions: 1) Can they only diagnose the catalytic converter via the computer codes as opposed to actually looking to see if the part is failing. 2) And if I do have to fix it, is there a cheaper alternative than the dealer, say Midas? 3) How long can I safely drive on it? I am not mechanically inclined and the guys at my non-dealer mechanic shop seem to be a little dismayed by the size of the job. Incidentally I'm going to bring it to them to take a look at it, but I'm not sure if they'll only be able to see what the dealer saw via the computer diagnostic. This car is turning out to be a very expensive thing to hold on to. Any suggestions would be helpful.

So I didn't go back to Midas--I listened to what people had to say about that. The engine light stayed off for a while then came back on with the 'transmission service required' light again and the car went into limp mode. I brought it to the dealer, mostly because they were near and could give me a loaner. I talked directly to the mechanic and asked if the cat, midpipe, and muffler had to be replaced (what they told me last time). He said he'd look at it again, but it just seemed like the cat if anything. I asked the service rep why he included the mid pipe and the muffler--he said he looked at my car records and it seemed that they too needed to be replaced--huh? "Seemed?!" Turns out those pieces are fine. They did the diagnosis and no cat codes came up. He said the transmission codes indicated I needed new speed sensors which they replaced $350--not cheap. I'm keeping an eye on the catalytic converter now. Hopefully it was just the sensors.

So I didn't go back to Midas--I listened to what people had to say about that. The engine light stayed off for a while then came back on with the 'transmission service required' light again and the car went into limp mode. I brought it to the dealer, mostly because they were near and could give me a loaner. I talked directly to the mechanic and asked if the cat, midpipe, and muffler had to be replaced (what they told me last time). He said he'd look at it again, but it just seemed like the cat if anything. I asked the service rep why he included the mid pipe and the muffler--he said he looked at my car records and it seemed that they too needed to be replaced--huh? "Seemed?!" Turns out those pieces are fine. They did the diagnosis and no cat codes came up. He said the transmission codes indicated I needed new speed sensors which they replaced $350--not cheap. I'm keeping an eye on the catalytic converter now. Hopefully it was just the sensors.

UPDATE:
So I took it in for a second opinion at Midas. The check engine light had come on again and Volvo was insisting it was a premanent catalytic converter failure (again $1780). When Midas ran the computer, no catalytic converter trouble came up--the code they read was P0717-transmission sensor A circuit no signal. They reset it then took it for a spin. The check engine light came on and the code this time was P1618 manufacture controlled output check. The friendly guys at Midas had me come in and inspect underneath the car to show me some of the casing on the catalytic converter was rusting but it was in no way failing and that I had probably another 5 years on it. Also the muffler and center pipe were fine.
HOWEVER, I just went outside and the cooling system was running WITHOUT THE KEY in the ignition. IS my computer messed up? ARG

The cooling fan (heater/ac blower) is supposed to run to dry out the evaporator, and the engine fan will run when the coolant is too hot. Both without the engine on. It's normal :)

Now, about the cat. Have an independent VOLVO expert look at your engine. Ask him if a cracked vacuum elbow could cause the codes. Do NOT go back to Midas unless you have extra cash to throw around, or he lives next door to you and supplies you with beer.

Klaus
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Please answer your responses. We need to know if the advice is good or bad. The 164 has a new home, all I am left with are 2 turbos :)

Don't you just love shops that look at the codes and say, that is your only solution? If the cat needs to be replaced, why replace the muffler? Did anyone ever check your vacuum hoses for leaks, which is what causes most of the cat code problems? 110K miles is less than half of what you should expect for a cat.
Are you having accelleration problems? Usually, when a cat goes bad, it gets clogged and the exhaust is no longer free flowing.
Ask the local indy shop if they can replace just the cat and there are cheaper alternatives out there.

Klaus
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Please answer your responses. We need to know if the advice is good or bad. The 164 has a new home, all I am left with are 2 turbos :)