Hi,
i have a 1995 Blazer 4.3L W vin I'm thinking my problem is a clogged catalytic converter.
I recently changed my muffler do to corrosion, but noticed a rattling noise and re-tightened connections. drove it for several days. Now I noticed that the muffler rumble is much quieter and have noticed a loss in power on excelleration. when you get into it you hear a whistling noise with no power until letting up on the pedal I checked the tail pipe for amount of exhaust pressure and it seems less than normal. Today on the way home at highway speed the service engine light came on blinked for a few seconds and then went solid, it repeated this one more time. I believe when it flashes it is detecting a bad condition at the cat. I removed the front o2 sensor and there
is plenty of pressure. Before spending a few hundred on a new cat I just wanted a second opinion from the Blazer forum community.
Thanks

 

Well, it sounds like a bad cat, but when you unplugged the O2 sensor, did you notice any change in performance? A flashing SES light indicates a potentially damaging engine condition (ie. multiple misfire), not a bad cat. Get underneath the cat and rap it with a mallet or your hand and listen for a rattle. If the cat's internals have broken up, they can travel to the muffler and restrict it.

 

dropped the cat today sounds like a can of marbles it's all broken up inside looked into the muffler and it seems fine thanks for the second opinion though

 

There ya go.