Catalytic converter issue?

Ok, long story short:

Got clutch replaced in my 5 speed manual 3 weeks ago. Got the car back, car runs great, I take it to the interstate, go up to 80 mph but can’t put it into 5th gear…turns out they hadn’t adjusted the shifter correctly! So when I tried to put it into 5th gear I ended up putting it in 3rd! Guess that can’t have been too good for the car at that speed…

Anyway, they sort out the alignment shifter, car goes goes to 5th normally, but now there’s a grinding noise when I accelerate in 3rd/4th and 5th gear…

Naturally assumed there was a problem with the clutch (I posted about it on this forum), but no, all good there.

Since then, my symptoms are:

-Less power when I accelerate in pretty much all gears
-rpms go up real high in 1st gear, seems normal in the others

  • fuel consumption has gotten worse

  • grinding/ rattling noise (still no mechanic has been able to tell me what it is)

  • new since last week: loud humming noise coming and going randomly

Everything seems to be pointing towards catalytic converter problem, but I just really want to hear people’s opinion.

Also, how could this suddenly happen after change of clutch…would something like that happen just because of the high engine speed that time I drove it in 3rd (wasn’t very long).

Any help would be much appreciated!


Sounds as if the clutch is slipping.

That’s the 1st thing I thought, but 2 places I’ve been to have said that it’s fine. Just not too sure anymore…

Forgot to say, I also have a new code that’s come up : p0340, apparently something about my ignition module. Could that be related to any of this?

You put it into 3rd at 80 MPH?? You may have over-reved and damaged the engine…A compression test will spot that…As for the converter, none of your symptoms point to that…

What is the model year of this Saab 900?

it’s a 98, only 90000 on it though.

P0340 a camshaft position sensor circuit malfunction. (I.e. it’s not necessarily the CmPS since that is only one part of the circuit). The car won’t run right with this issue.

Here is some info:

I can’t tell you if that will explain all of your symptoms - but you might have more than one problem. I can say that I would be reluctant to try to sort anything out until clearing up the cam sensor issue.

Good point cigroller! the p0340 code description says the symptoms could be:

Hard starting or no start- Rough running / misfiring- Loss of engine power

In a way that makes sense, since the car does struggle a little bit to start compared to what it was like before and I definitely have loss of engine power.

Now, would you recommend taking the car to a saab mechanic specifically about that?

Well, that depends on whether or not you have a SAAB specialist who is worth a darn. If you do, the it’s probably a good bet. Cam sensors are quite generic as things installed on cars - but many makes/models often have their own little quirks about common issues. Yours might not be common or particular in any, but if it is I’d imagine a SAAB specialist would be best.