2000 C3500 350 exhaust shortening

northeastnick · Jan 10, 2022

Good evening all, I have a 2k C3500 cab and chassis RCSB. I am looking to shorten the factory exhaust system while maintaining the OEM muffler. I would like it to have a side exit with a turndown immediately behind the cab. What I am unsure of is what exactly I'd have to do to keep all my O2 sensors and fool the system into thinking all is normal. Haven't learned much about this stuff yet so any info or advice would be much appreciated

Schurkey · Jan 11, 2022

1. Why? What do you think you're going to gain?

2. Better make sure it's legal in your state. Some places really frown on exhaust systems that don't exit behind the rear axle.

3. You can't legally change the location of the catalytic converter(s). Therefore you can't change the location of the rear O2 sensors. Therefore, I don't expect you'll be able to shorten the exhaust as much as you want.

F4U-1A · Jan 11, 2022

Had to cut the pipe off aft of the muffler before it curled over the rear axel. This was 20yrs ago (short story-- me wife's fault) , never had any issues (no codes) with the 5.7 vortec. Would not pass a safety inspection here I think.

GoToGuy · Jan 11, 2022

Hot exhaust flows into rear tire, it will raise tire temp. Exhaust streaking down side of vehicle.

evilunclegrimace · Jan 11, 2022

GoToGuy said:
Hot exhaust flows into rear tire, it will raise tire temp. Exhaust streaking down side of vehicle.

Not likely

northeastnick · Jan 11, 2022

Appreciate all the responses, I'm just moving it up so it's not getting stuffed into things when the flatbed goes on and it'll be routed away from my work area at the rear of the truck. It's so far away and ain't directed at the tire, in theory it's plenty of room for it to mix with the ambient air at any speed. I'm aware I am still legally required to have my cats and don't plan on hacking it up too bad. Don't like the hefty sum the feds want if they catch you without em.

Frank Enstein · Jan 11, 2022

Just cut and paste the pipe behind the last O2 sensor. Having the muffler closer to the engine will increase the back pressure slightly.

Perhaps another option is to do a 180 out of the muffler so the pipe goes forward an then put a 90 on it to dump it out the side. Not sure if that will help.

northeastnick · Jan 11, 2022

Doing a 180 and then out definitely seems like the better option, that way all the sensors stay where they need to be. I don't mind experimenting with the stuff, so I'll head over to the parts store and pick up some angles this weekend to mess around with that. I'll keep ya posted on it, thanks!

Frank Enstein · Jan 11, 2022

You're welcome. What size is the exhaust tubing on the muffler outlet?

northeastnick · Jan 11, 2022

Should be 2.5 if I recall correctly, pretty sure it's the factory system still

2000 C3500 350 exhaust shortening

northeastnick

Newbie

Schurkey

Supporting Member

F4U-1A

Early spring 24

GoToGuy

I'm Awesome

evilunclegrimace

Does not always play well with others

northeastnick

Newbie

Frank Enstein

Best. Day. EVER!

northeastnick

Newbie

Frank Enstein

Best. Day. EVER!

northeastnick

Newbie

Similar threads

Latest posts

Members online

Forum statistics

Share this page