Cutting off Exhaust behind rear axle?

[Engineer]

I know this has been done but I can't find the threads. Was crawling under the truck today and thought about chopping the exhaust off behind the rear axle towards the end of the downward diagonal section. I see that I will loose a support hanger

*Did you notice any audible increase in the cab?
*Did it help with the sulfur/exhaust smell with the rear window down under acceleration?
*Any other issues or concerns this could cause?

 

[Raven]

You might get a new rattle without that hanger.
Then there is the possibility of exhaust gasses leaking into the cab from the shortened exhaust. (The engineers put that pipe there for a reason!)

Every old clunker I had (most of my vehicles, LOL!), when they developed the inevitable muffler or exhaust leak, the exhaust smell was quite noticeable in the car. (Of course, it makes you appreciate the tree huggers more, when you are constantly smelling the by-products of your driving habit).

 

[<<<<]

Don't do it. Carbon Monoxide intrusion is a realy nasty risk.

 

[philsey]

I've seen several threads where, to alleviate exhaust entering the rear window, owners have had a muffler shop bend/reroute the tailpipe behind the rear wheel.

I certainly would not cut it off underneath the vehicle.

 

[1engineer]

That's the ghetto way to do it and you are better than that. Get a muffler shop to do a turn out behind the right rear tire.

 

[AirspeedX]

That is pretty ghetto. I used to do that stuff on the farm when I was 16.

The other problem I can see by doing that is you're blowing moisture up in your undercarriage all of the time.

 

[Erkelbot]

As others have stated, just have a muffler shop bend a bit of metal and have the exhaust tip point toward the back of the rear passenger tire. I did this with my 3rd gen and 4th gen, and it all but fixed the sulfur smell with the hatch window down under acceleration.

 

[BlackWorksInc]

I'll be honest, I just cut my exhaust after the axle pointing downwards. I have been meaning to get it to a muffler shop/weld a bent pipe to it to get it routed towards the rear wheel, but its pretty low on my list of mods at the moment.

I haven't seen any real downside to doing it this way and exhaust fumes haven't been an issue, even with the windows down when in motion or stopped. (I let my friend drive sometimes, so I've been in every seat in my 4Runner, including relaxing in the cargo area when we had 6 people to run to the city and back this weekend.)

I wouldn't say its the safest option as theoretically you could get carbon monoxide seeping into the vehicle, but I honestly haven't experienced that at all. A few people have done it on their 4th gens as well. I would say that if you are going to cut it after the axle, make sure the cut is at an angle so the pipe points downwards towards the wheel wheel rather than straight to try and push fumes from under the vehicle to get the best possible evacuation. Bottom line, if you're that strapped for cash, hacking it off at the axle is possible; but I'd say spend the money and get it done right (which I need to do eventually... >.< )

I wouldn't mind testing the vehicle for exhaust fumes, but I don't have a C0 tester. Would be an interesting experiment though.

 

[Engineer]

I'll be honest, I just cut my exhaust after the axle pointing downwards. I have been meaning to get it to a muffler shop/weld a bent pipe to it to get it routed towards the rear wheel, but its pretty low on my list of mods at the moment.

I haven't seen any real downside to doing it this way and exhaust fumes haven't been an issue, even with the windows down when in motion or stopped. (I let my friend drive sometimes, so I've been in every seat in my 4Runner, including relaxing in the cargo area when we had 6 people to run to the city and back this weekend.)

I wouldn't say its the safest option as theoretically you could get carbon monoxide seeping into the vehicle, but I honestly haven't experienced that at all. A few people have done it on their 4th gens as well. I would say that if you are going to cut it after the axle, make sure the cut is at an angle so the pipe points downwards towards the wheel wheel rather than straight to try and push fumes from under the vehicle to get the best possible evacuation. Bottom line, if you're that strapped for cash, hacking it off at the axle is possible; but I'd say spend the money and get it done right (which I need to do eventually... >.< )

I wouldn't mind testing the vehicle for exhaust fumes, but I don't have a C0 tester. Would be an interesting experiment though.

Thank you for the thoughtful reply, While I think the concerns mentioned are valid I wanted to accomplish 2 things, minimize smell with rear window open and have the exhaust pipe not visible. Sounds like cutting it would accomplish those things. If i do it I could use my home CO monitor and leave in the car and let it idle on a non windy day for a couple hours(not real scientific here) While I have no data I think the chance of getting CO poising from doing so is about the same as the increased risk most run by increasing our stopping distance and emergency handling with other modifications (additional weight etc). If I go down that path over the holidays I will report back.

 

[mikey's2010SR5]

I also have mine cut so that it points down towards the ground. I had smashed the tip numerous times and then with the rear bumper it just made sense. Granted I don't drive with my rear window down, but other then that I don't get any smell in the cabin. The sound is not any different and I don't have any new rattles from the pipping.

One photo

 

[Engineer]

Thanks, exactly what I was thinking

 

[JEMP1003]

Thanks, exactly what I was thinking

Did you ever do it? I smashed the tip of the exhaust, and debating whether cutting it of completely or bending to the side.

 

[rochmpr]

I cut my tail pipe off as it makes the turn to horizontal behind the axle. Would have no issue doing it again. I have driven around plenty with the rear window down with no issues as to fumes. No real change in sound as you are just shortening the tail pipe.

Go for it.

 

[Engineer]

Did you ever do it? I smashed the tip of the exhaust, and debating whether cutting it of completely or bending to the side.

Yes I cut if off where it turns down after the rear axle, I did notice that I have melted a bit off the rear mudflap so I should have cut it differently or just spent a little cash and had it routed out the side.

In relation to the photo above, I cut ~2-3" further up which is before it starts routing to the rear and is exiting angled toward the ground/mud flap

 

[WhiteRice]

From years of racing I can tell you the last thing you want is exhaust gasses building up under a car. Not only do you have the smell and build up of carbon dioxide but the additional heat can be very dangerous to components (i.e. brake lines) that are not used the the exposure of additional temps.

I had a shop here in Houston (after reading some reviews of from a few of you in here) cut the pipe just ahead of my rear axle on my '16 TE and do put a side exit on. I asked them to do it with a sleeve clamp so I can revert back to my stock set-up if I ever want to. Total out the door for this was $45 and took all of about 30 minutes.

Will post some pics and the shop name once I can get back to a decent cell signal.

 

[WhiteRice]

AFFORDABLEMUFFLERS.COM

 

[BlackWorksInc]

[MENTION=145203]WhiteRice[/MENTION] That's how I'd like to get around to doing mine I think...

I still haven't noticed issues with exhaust smell from my vehicle intruding into the cab. I think cutting it after the axle so the exhuast is pushed down and towards the outer edge of the vehicle seems to help with that.

Still don't disagree that it's not an ideal solution, but it hasn't killed me yet (knock on wood) for those who are wondering. Makes putting an exhaust hose on it at work a pain though...

 

[Boyds4Runner]

I did something similar to what [MENTION=145203]WhiteRice[/MENTION] did only the pipe extension was welded rather than a sleeve.

I don't know how anyone is getting this done for $45.00 or less. Where I live it was $150.00 for everything and about an hours work.

http://www.toyota-4runner.org/5th-gen-t4rs/224467-5th-gen-tailpipe-redirect-add-second-rear-anchor-recovery-point.html

 

[Saker]

Something similar as well......

I already had the SS 4Runner Exhaust tip, so I bought the following off of ebay.
Yonaka Part# YMSS9025
Fully Polished!
304 Stainless Steel
2.5" OD 90 Degree Mandrel Bent Pipe - 6" Legs
1.5 MM Thick - 17 Gauge
Yonaka 2 5" Polished 304 Stainless Steel 90 Degree Mandrel Bend Pipe Tube 6" Leg | eBay

The guy I used (doing this for 20 years at his own shop), cut the OEM pipe just behind the hanger, cut the new SS pipe just before one of the bends, expanded the opening so he would be able to angle it down (so it would not be pointed down, but horizontal), but still fill the gap with the welds.
Before welding, he measured where the tip would be positioned, cut off excess amount of pipe for the side exit, flared the end slightly and welded to the OEM pipe and then my tip on the SS pipe.

It would have looked good with the SS pipe exiting without the tip as well, but since I already had it.....I told him to weld it

He did this effortlessly without issue!

OH, he charged me $40.00 out the door. :reddance:

 

[WhiteRice]

Went to two places in the West Houston area that seemed either scared to do it or were trying to sell me a complete system stating that "it wouldnt be practical". Found Affordable Muffler mentioned in here, called them up and the owner (Emmanuel) said to bring it down. He made it so it would literally only take me avout 15 minutes to swap it back to stock. The primary reason for doing this was because I have a tow mount basket that I use for surf fishing and did not want the exhaust melting my cooler or any of my gear. Could not be happier with the end result AND the price