Cat. converter, muffler, something else?

[GpB311]

Lately Ive noticed the sound of my car seems different and it feels a bit sluggish. It sounds kind of like those cars with cheap exhaust systems on them do, at least in my mind. Ive gone all the way up and down the exhaust system and there is no leak anywhere. I also went ahead and cleaned the intake filter, throttle body, and checked the spark plugs.(Only about six months old)

Its a 4 cylinder chevy cobalt thats got about 120,000 miles on it and the exhaust is all stock, so Im wondering if something along the line is causing a blockage or is just getting old. It hasnt thrown any check engine lights just yet either.

Heres a short video showing the sound, although I dont have one from before it started sounding different.
Car Sound

 

[Warstud]

If you suspect a clogged Cat. Try removing the 02 sensor before the Cat to see if it performs better.

 

[3800Series]

If it's the cat you can look at live data from the o2 sensors to see if it's working right. If it doesn't look right to our and buy a infrared laser thermometer.

Check the temp leading to and exiting the cat.

There is plenty of videos to show how it's done on YouTube. If it check out then the cats good.

 

[Merkava_4]

Do an exhaust back pressure test. Remove the upstream oxygen sensor and thread in a back pressure gauge in its place. Anything over 1.0 psi is considered clogged.

 

[Lubener]

Originally Posted By: Warstud
If you suspect a clogged Cat. Try removing the 02 sensor before the Cat to see if it performs better.


A vacuum gauge is easier.

 

[oilpsi2high]

Check the flexpipe between the manifold and cat, those are known to go bad.