Sluggish performance

[sroney]

I have a 2000LS that I purchased when the car had around 32K miles. It now has roughly 147K miles. One of the main reasons I purchased the car was the outstanding performance.

Lately however, the performance (and gas mileage) is nowhere near where it should be. In fact, I recently drove a rental with the 3.4 liter engine and felt like that car would blow my 3.8L away.

The engine feels like it cannot "breathe". I have a K&N filter installed, and it is clean.

There are no codes being thrown, plugs and wires are fairly new, and all maintenance is up to date.

Does this sound like a clogged catalytic convertor? Is there any way I can tell if it is the convertor?

Thanks for any input.

[Iflylow]

Plugged cats don't always throw codes. A mechanic can do a backpressure test for about $80 and tell if it is the cat. The early Impalas had an issue with the cat material breaking off and plugging them up. GM warranted it, but I think for only 80K miles.

[sroney]

Thanks for the input.

I'll have them check it out.

[j cAT]

if you never changed the o2 sensors it is very possible the cats are restricted. this usually results in a slow loss of power and economy make sure you replace the o2 sensors when you change the cat......

[sroney]

I actually have never changed the O2 sensor. I'll check that.

[Iflylow]

There are 2 O2 sensors. One upstream of the cat, that controls the fuel mixture, and one downstream of the cat, that tells the computer whether the cat is working properly or not.