my son's 850 is very noisy, appears to be catalytic converter. Muffler was changed about 2 years ago but it did not fix the noise. The car was driven very little until now so the noise did not bother anyone, now my son got it and drives every day.

ALSO, there is significant power loss esp. at high speeds (>50 mph) -could a clogged CC cause noise and power loss? and cause increased fuel consumption?

thank s

 

The easiest way to find out of it is the cat is to climb under there with a rubber mallet and tap on it and see if you hear something rattling in there.

 

Any unusual odor from the tail pipe?

Any blockage in the exhaust system can cause all symptoms you have described, as the engine has to work harder to counter back-pressure.


JPN

 

If you can smell an egg type odor, the cat is bad. As advised by Tech, don't forget the heat shield at the manifold to down pipe area. Good luck!

 

yes, it does rattle, but the car passed the state inspection last year just fine.

 

If it rattles the cat came apart inside. eventually parts of it will work to the back and reduce flow and starve the car reducing power.