whistle from exhaust

[saturn]

the dealer says I'm crazy, but I believe the catalytic converter on my girlfriends 02 legacy L wagon is clogged, causing back-pressure and a whistle at higher RPMs.

in fact, there's a code in the system for catalytic converter inefficiency -- which means they have to replace it under the federal 80,000mile/8year guarantee... except the service guy still charged me $50 to look at it.

he's betting me that the new cat won't fix the problem, because the mechanic has been fixing subarus for 30 years and never saw a catalytic converter make the exhaust whistle...

am I crazy? I thought this problem was common!

[2.5GT]

exhaust leak perhaps?

[saturn]

nope. there was one but I welded it up. there is backpressure coming from the cat converter... so I'm basically 100% positive it's the problem (I've run into the same problem on other cars with bad cats)

I'll post an update when they replace the cat (they only ordered it)... my guess is it'll fix the problem. if it doesn't, I'll replace the resonator with a $15 cherry bomb and the muffler with a nice borla exhaust.

[dplacencia]

It's the muffler. I've had several of them making that noise at work.

[sansMYSTi]

Get a SPT axelback and the whistle will be gone.