Cat Only Exhaust?

[Zilverado]

So I removed my rusted out muffler and tailpipes on the weekend, but have not reinstalled a muffler. I just left the intermediate pipe coming out of the back of the cat. I actually like the sound of the exhaust running through the cat alone - kinda "growly" without being too loud.

However, I know my wife doesn't like it very much, so I will likely install the muffler - - sometime . But, in the meantime, is there any problem with running the vehicle this way - cat only? I assume fuel consumption and performance may be effected by the reduced back pressure, or is this all a bunch of "hot air" :p .... sorry, bad pun.

Any thoughts?

[KShortell]

Well, there is a bit of danger for carbon monoxide poisoning or possibly starting a grass fire somewhere...

[apstguy]

I have had it that way for about 4 month now. No problems. I think my cat is plugged anyways.

[1FaastC10]

replace the cat, and have tailpipes run out like stock. i've got the same setup on my 91 with dual tailpipes out the back. i didnt care for it at first, becuase i like a low rumbly exhaust note. its actually starting to grow on me.

[NoLegs]

Originally posted by Zilverado
... But, in the meantime, is there any problem with running the vehicle this way - cat only? I assume fuel consumption and performance may be effected by the reduced back pressure, or is this all a bunch of "hot air"

Some people believe that valve warping that occurs with "straights" or open headers is because of the back pressure (or lack thereof). Actually, it's a result of cold air hitting the hot valves and cooling them too fast. With a full system, everything cools down over a longer period of time with ambient temperature and let's your valves cool down properly. This shouldn't be too much of an issue, because the Cat will slow down any cool air trying to rush in there.

So, your only problem I really see here is a little bit of toxic fumes entering into the cab while your driving, probably not something you want with winter coming up, just in case you ditch your rig and have to sit with your engine running for heat.

[Zilverado]

Thanks for all the feedback Guys - good points.

After driving the truck for a while like this, it's starting to annoy me a little . The fumes (as some have mentioned), as well as the noise. These could be solved by extending the pipe to the back, but if I do that I may as well put the muffler back there as well.

So, looks like me and my mig will be spending some time under the truck this Saturday, replacing the muffler.

Glueing steel together with fire - cool...