plugged cat converter on montero...anyone else?

[jluck]

I suspect my catalytic converter is plugged or plugging up In my 95 SR. When shutting down the engine I get a wheezing sound,my fuel mileage is not good and top speed performance is lacking. With these rigs being known oil burners I think its junk. Anyone else plug there converter? Any other suggestions? Thanks.

 

[scrubber3]

My cat is fine and I still have the fuel mileage not being good and lacking speed..It is a Montero right?...As for the wheezing sound-well, it is January...













Okay, really I'd do a proper diagnoses first. It is possible that The catalytic converter is melted and has blocked your exhaust system, but before you go pointing the finger you may want to either go ahead and get an exhaust pressure test done or go ahead and see about diagnosing the fuel system and possibly the ignition system as well. Typically an exhaust blockage means the vehicle will basically fall flat on its face after the exhaust pressure builds up. The wheezing sound could even be the evaporative system. Do you ever fill the gas up and keep right on putting gas in it even after the pump stops just to get an even number. You may have a gas filled canister... That will cause every one of those symptoms. Another culprit could be the fuel pressure regulator and/ or the fuel pump... Food for thought!

 

[jluck]

The noise it makes is more of a belch of air coming back through the air cleaner, not a constant wheezing or whistling. It's like the engine has excessive pressure built up and when I kill the engine it comes out the air cleaner similar to a turbo motor letting off excess boost. I did notice this before the K&N also. The check engine light also comes on and goes off periodically.
all of these things are conducive to cat failure from what I researched on-line. (and the INTERNET is never lies.... )

I am going to pull it and make sure it's "free flowing" type as we don't have smog testing around here.

 

[shmabs]

Cat

Most Cat's have to "light" to result in a good burn of all the nasties. If you have one of those point and shoot thermometers its a pretty easy to see if a cat is lighting off. I'm not sure of the exact temp, but it will be a lot warmer than the rest of the exhaust. Thinking about it more, a clogged cat might not ever get up to temp, so it could read super cold as well?

Mike

 

[scrubber3]

Actually a clogged cat will get extraordinarily hot.

 

[rxinhed]

The cat plugged on our first Montero, just enough to limit the exhaust flow, melt the exhaust manifold and two valves, and burn the hood from the bottom side. The repair cost was almost the purchase price of the Montero, wife without car for 1 week made me no friends.

 

[shmabs]

That makes more sense, restricted flow and no where for hot exhaust to go. not sure what i was thinking earlier.