Time to replace stock exhaust, need ideas (1 Viewer)

[danmc00]

Im looking at replacing my stock exhaust. Pretty sure i have an exhaust leak somewhere and I’m looking to help prevent some of the exhaust smell. Where is the best place to have the exhaust come out to help with the smell. Ive seen some put it out the back and some put it out the passenger side behind rear tire. Ive seen some add a small catalytic converter as well to help with the smell. Goal is to drive mine to work some days but not smell like gas/exhaust when i get there. What size pipe should i use since I’ll be going to a custom exhaust shop? Sorry for all the questions, just trying to cover my bases before i go over to the shop. Appreciate any feedback

I have a stock 2F with sniper fuel injection

 

[charliemeyer007]

The last time I did mine it was complete set from Man-a-fre to go with their header that was given to me. You should see what your local shop(s) want to charge to hook you up. I would consider stainless steel if I planned to keep it forever. I wouldn't add a cat period. Just dump it out the back or in front of a rear if you have or expect to add a rear aux tank. 2" is enough , even with a full length pipe its quiet enough - I ran with a cherry bomb.

 

[igotta40]

What year is your FJ40?

 

[pb4ugo]

Usually folks want the exhaust to exit out the side or corner of the vehicle. The exhaust fumes tend to circle back towards the vehicle when the exhaust exits straight out the back and you'll smell it. There's several vendors that sell kits on this site. The search function works well either here or use the internet and click on any result that references this site.

 

[Grayscale]

Stock exhaust manifold, or header pipes?

 

[Mike Shull]

Usually folks want the exhaust to exit out the side or corner of the vehicle. The exhaust fumes tend to circle back towards the vehicle when the exhaust exits straight out the back and you'll smell it. There's several vendors that sell kits on this site. The search function works well either here or use the internet and click on any result that references this site.

X2 on this comment. I’ve had single and dual exhaust straight out the back as well as angled downwards. The exhaust came back inside of the Cruiser each time. I’ve also had dual exhaust exit under the doors and I had major drone.

The best results that I’ve experienced is when my exhaust exited out the side corner 45° from the frame, both left and/or right (dual and single exhaust), or with the factory exhaust exiting 90° from the frame out the passenger side. I’ve had nearly a dozen exhaust systems on this vehicle.

Given this, my exhaust has recently been redirected back out the rear due to space limitations with my 4-link suspension and anti-rock links. I don’t have a top on it yet but the body is brand new and so far (600 miles) I’ve never smelled exhaust though I am running a different engine than before with fuel injection and a cat.

 

[B y r o n]

"Goal is to drive mine to work some days but not smell like gas/exhaust when i get there."

I think you need to identify the source of the smell first. Could the smell be coming from leaking fuel lines inside/or out. Cracked vent or fuel lines will cause a smell and is a common source.

What is the condition of your current exhaust and where does it exit?

 

[danmc00]

It’s a ‘78 with stock manifold and exhaust at the moment. I just had Sniper fuel injection installed and the smell was happening before that as well. It’s more of an exhaust smell than fuel itself. Current exhaust seems ok but haven’t dove into it much. It exits out the passenger rear now.

 

[pb4ugo]

No affiliation.

FJ40 Mark/Downey Header

Is this a Mark’s/Downey header? Are the headers interchangeable between the F and 2F engine? I plan to install on an F engine.

forum.ih8mud.com

 

[BigDogg]

I had a similar problem... turned out to be a cracked exhaust manifold...

 

[Hayden70FJ40]

I have a man-a-fre header on my 1F, Holly sniper also installed. I used to also get bad fumes in the cab. I daily drive mine. I ended up putting an oil catch can on it from the tappet cover. Also kept getting the oily vapor smell. so did another catch can but this one with a filter on the can then to the valve cover. no vacuum ran to it, the tappet cover catch can I run to the manifold and the air circulates and pulls fresh air from the valve cover catch can solved my oily vapor exhaust like smell. I tried just running a filter directly on the valve cover like most do, but kept getting the nasty smell. then after all that like yourself I wanted the exhaust smell gone also. I run a 2 3/4 header back exhaust with a thrush chambered muffler. I used to run an axle dump system when it was open cab and it did fine tell I put the top on then it was nasty smelling. so I did a tailpipe on it similar to em out behind the driver side rear tire. It helped a ton but still kept getting a lil smell and my passengers would get headaches. so ended up putting a down draft section on the end of it and that took away almost all of the smell. I off road and crawl with it a lot so I still was able to tuck it away a bit. if I ran it lower Im sure I could eliminate the smell fully but don't want to smash it on rocks. sorry for the long message but that's what I did lol. Also if your sniper isn't fully tuned properly and its running very rich it will really really smell, when I installed mine and was in the process of tuning it, it was definitely very very rich from out of the box. running my AFR at 15 and 14 at idle and it likes it a lot. when I first installed it, it kept running at 11 and man it stunk. the fuel prime also was a big factor also mine kept priming 100% at start up so it would flood the intake then it would fire up and lope like a cigarette boat and cover the ground in black exhaust lol I turned the fuel prime all the way down to 20% and that solved a ton. the holly system is amazing but to be safe they have it running rich, rather than lean and getting angry calls from customers engines running hot and lean. rich is safe but stinky. Also make sure your PCV is good oily vapor smell and exhaust are similar. a plugged PCV can actually cause oil vapor to come up threw the distributor, has also happened to me, distributor would actually drip on driveline

 

[Hayden70FJ40]

 

[wimberosa]

I had a similar problem... turned out to be a cracked exhaust manifold...

Does anyone have a positive or negative opinion on whether adding a exhaust flex pipe is good or not? I'm looking a bit at the exhaust mounts on the 1979 (the mount to frame below the exhaust manifold) and am thinking there may not be a lot of flex there. The 2F engine doesn't rock like a performance engine .... so not a lot of back and forth wiggle on the motor mounts ... but still wondering if we get cracks due to too rigid of an exhaust setup?

 

[charliemeyer007]

I have never had a issue without one - but I don't think it would hurt. Depends on the cost to do it.

 

[wimberosa]

Actually...that rigid mount on the 79 may be attached to the tranny and thus would rock with the engine (looking back at pics from others). I never had this mount on mine...but will probably try to route over the frame rail in this area instead of under.

Disregard all my blathering. I didn't intend to hijack this thread with my random thoughts.