Exhaust leaks questions

[Scotts96sploder]

I have cracks in both manifolds, at some point I’ll be replacing them with some cast manifolds if I can junk yard them up. I also have some leaks in the muffler somewhere behind the heat shielding.

I’m feeling kind of lazy and ratty, I noticed there is a flange after the cats I could just unbolt everything downstream until I have money for a proper system.

Question:
Will there still be enough back pressure via the cats so the computer doesn’t lose its mind?

 

[974X4BLACKSPORT]

Unbolting the exhaust system after the cats. will only make it very loud and extreme dangerous due to exhaust gases entering cabin. Leave everything in place until you have the new parts to fix everything. Also, unbolting after the cats. lets hot exhaust exit directly next to the fuel tank, BAD IDEA!

 

[Scotts96sploder]

Good point

 

[Mbrooks420]

It’s actually not very loud at all with no muffler. The cats have plenty of restriction.

 

[bertomax]

It’s actually not very loud at all with no muffler. The cats have plenty of restriction.

I was Thinking that would be a great idea if it wasn't real loud.

 

[Mbrooks420]

There’s no real benefit. You won’t see any real performance gains.

 

[Scotts96sploder]

So I got in there today just to mess around. Decided to see if the manifold bolts would budge. Every one I could get a wrench on easily came right out! I was really worried about that part.
Looks like the ac compressor needs to come out to get to the last bolt on the driver side, other than that the cast manifold swap looks fairly easy. Anyone know where to find an EGR cap?
My plan is to leave the first cats stock and delete everything from there back. Maybe a Chinese glass pack. I kinda wanted to dump is out the side but I don’t see a convenient place to do that.

 

[BruceExploder]

I am in the process of doing same thing.

 

[Scotts96sploder]

View attachment 170902

I am in the process of doing same thing.

Are you going to use those manifolds?
Are you leaving the second cats in?
So your dumping it straight down, basically in front of the axel ish area? I dig that, might do something similar.
I’m looking for the cast manifolds from a 98, rock auto is sold out and summit is overpriced.

 

[BruceExploder]

Yes only cause i found them and the EGR brand new on a junkyard vehicle it literally still hard the ford tags on everything. I am going to get headers eventually so these are just a placeholder for the time being since my EGR tube has a huge crack.

I am going to leave the cats and do everything from the flange back. that way i can weld up whatever off of the vehicle and make my own cat back and change it latter on just bolting it back up to the flange.

local muffler shop was trying to charge almost 500$ to do that plus remove the rear cats so i was like whatever i can get a harbor frieght welder and do it cat back myself. muffler was 26$ some new pipe extentions may cost about 14$ then a welder 90$ will work out way cheaper for me.


i played with different combinations of stuff just clamped down and it was leaking out so i am going to weld it and i did like the way it sounded dumped the best.

 

[Scotts96sploder]

Did you get the harbour freight stick welder? I definitely have one of those. I’m probably stealing your idea, I found a dual in single out for the same price, reversible and all that. Less to weld.
I just tried running with the cats open, it’s just a touch loud above 3k lol, but you can’t hear the leaks anymore!
I might see if I can modify what I have for rite now while I’m waiting on parts

 

[BruceExploder]

can you link the dual in single out? im curious

 

[BruceExploder]

Did you get the harbour freight stick welder? I definitely have one of those. I’m probably stealing your idea, I found a dual in single out for the same price, reversible and all that. Less to weld.
I just tried running with the cats open, it’s just a touch loud above 3k lol, but you can’t hear the leaks anymore!
I might see if I can modify what I have for rite now while I’m waiting on parts

not stick im going to get a flux welder. not sure if stick is suited for exhaust work

 

[Scotts96sploder]

I found it on the main website and then searched amazon.

TOTALFLOW 42198 Straight Through Deep Tone Performance Muffler - 14" Body Length / 20" OAL - Oval 5" x 8"- 3" Center / 2.25" Dual"Reversible/Bi-Directional"

 

[Scotts96sploder]

View attachment 170902

I am in the process of doing same thing.

Where did you find the pipes from the flange to the muffler? And what are the sizes?

I’ve been rolling around with just the cats and I really like it, but I’m gonna put a muffler in there just in case a cop is having a bad day.

 

[Scotts96sploder]

So my father in law just told me that these are not cats.
It was my understanding this had 4 cats and these are the secondary’s? Can anyone confirm? I feel like I’m taking crazy pills rite now lol
Anyhoo I really like how it sounds open like this! I bought a coupling to practice welding with and all I have is 6013, so if I can make that hold pressure, I’ll get some 6010/11 and the parts to make the rest.
Also I know I’m tap dancing around a big no no for this forum, so let’s just assume “I will NOT be cutting these out and replacing with straight pipe” and leaving the ones up front. Lol
Any welders here want to give me some tips for stick welding exhaust that don’t involve not doing it?

 

[CDW6212R]

All four are cats, the rears are just redundant, and the rear O2 sensors also just double check that the front sensors are working properly. The only proper way to replace cats is when the others are malfunctioning or old and believed to be not working well. Having two is mandatory and proper, I will always install one per bank on my cars(but mostly for the sound reduction).

 

[BruceExploder]

Pipe size is 2.25. I used a 2.50 to 2.25 adapter off the flange to even it out then used all 2.25 stuff from there.