Hi all,
I have a '96 850 turbo. I started getting poor performance and mileage when the check engine first came up w/ catalyst error code. I reset that. Then came 02 sensor code, then misfire cylinder 3 code. I reset these and got catalyst again. So, I went to the shop (Cinderella Carriage in Cambridge, MA where I live) and they replaced my catalytic converter ($1600). They must not have road tested it b/c it idles poorly, power is down, there is a lot of exhaust which smells horrible and mpg is down ~%50.

Now I have two new error codes: too rich bank1, too rich bank2. The vacuum system was totally overhauled 3 years ago, both 02 sensors have less than 40K miles on them.

Before I let the shop in there again, Is my MAF going? Can I test this somehow? Can I replace this myself?

THANKS in advance!
Marcus

Try to disconnect the battery for 15 min and see what happens. This will force the ECU to reset the fuel tables. The engine will probably run a little rough at first 'til the fuel settings are adjusted. Be sure you have the radio reset code handy.

Have you checked your fuel pressure? Maybe it's too high - bad regulator. That could cause multiple misfire and 02 symptoms. As the other post said it would be helpful to have the history of your codes if you know that.

Usually if the MAF sensor fails the car will not start.

Even though you say the vacuum hoses were overhauled three years ago, sounds more like a vacuum leak than anything else to me. Probably not hard to replace the MAF, but I doubt that that's your problem. Would help to post the numeric codes, by the way.

--
'96 850 and '83 244 DL both at about 200K; gone but not forgotten '81 245 and '64 Amazon

Thanks for the replies everyone. I'm new at reading codes and failed to get the details of bank/sensor (I know, that's probably most important...) but here's what I jotted down:

Before the new CC (in order of appearance):
-P0420/430 Catalyst System Efficiency Below Threshold (Bank ?)
-P0303 Cylinder 3 Misfire Detected
-P0420/430 Catalyst System Efficiency Below Threshold (Bank ?)

The codes with the new Cat Conv (appeared simultaneously):
-P0172 Fuel Trim too Rich (Bank 1)
-P0175 Fuel Trim too Rich (Bank 2)

That they both showed up at the same time is odd. Possibly resetting fuel trim table will do the trick, though I wonder what the shop might have done (besides fleecing you). If the CAT was changed, it would be because there was obvious failures in it or because everything else was eliminated. 1600 is WAY too much to drop on a customer if you don't KNOW that there's not any vacuum leak or other things.


I'd bring it back, and if they say something to the effect of an air leak, I'd demand to know why they replaced the CAT. In fact, I probably wouldn't reset the trim before I went up there, they caused this problem by 'fixing' the old one.
--
If you're not driving it "like its stolen," are you really driving?

Any time the oxygen sensors/cat are worked on, the long term fuel trim tables (part of the ECU) need to be reset as fixit suggested. It the shop didn't do it, you need to. If these codes come back, then hunt for all of the possible vacuum leaks. The hard-to-find elbow on the left side of the intake manifold is a common culprit, but also check around the vacuum tree, connections to the turbo, etc.

--
'96 850 and '83 244 DL both at about 200K; gone but not forgotten '81 245 and '64 Amazon

Again, thanks all for the replies.
I asked the garage why they didn't road test. They said they did but I don't think so as idle was rough in the parking lot when I picked it up (after hours). They assured me that they'll cover any mistakes on their part and are looking at it today. I'll ask them about the trim tables.
Stay tuned (literally).

Well, the garage told me that while they were replacing the CC, the mechanic broke the front 02 sensor. They replaced it, checked for vacuum leaks, reset trim tables, etc. (at their expense of course) and the car is back to its old, peppy self.

When I asked why they replaced the CC they said that they drove it and it sounded like it was bad and then they found a hole in it. I asked to see it but they said it had already been shipped off to someone for reclamation of the precious metals inside.

To be fair, I looked at my receipt from 6 months ago when they replaced a ball joint and they had noted a "small leak in the CC" so, in the end, I can live with $1600 for a new CC and 02 sensor. Most importantly, my old 850 is alive once again.

Thanks for all your help!

Good to hear they made things right. I think its always a great feeling when the car is back to its 'sporty' self...
--
If you're not driving it "like its stolen," are you really driving?

I just did a quick Google for Cat converter pricing.
$163.18, 209.98, and 329.78
They charged $1600? Holy mackeral! What do they charge an hour?
Time for a new garage.

There's two good places near me:
Superior Motors in Salem
Lab Motors in Marblehead
They are factory trained Volvo guys on their own.
Maybe a 30 minute drive from Cambridge.

Bill in Swampscott

Thanks for the recommendations Bill. I think those prices are for refurb's. Anyway, they charge $130/hr. They've been good to me for ~10 years now (240 and 850). When they told me the quote, I called the dealer who quoted me pretty much the same thing so I went ahead. If I can't figure this out, I'll try the N. Shore guys.

I was talking to Bob at Lab motors today, he just rolled his
eyes at the hosing you took. Those prices were for after market cat converters.
Leave a phone nr or email if you want to yack.

Bill