Finally started my exhaust.. w/ pics (1 Viewer)

[scrowley]

Custom Exhaust with Pics

I have been living with code PO420 for awhile now due to some bad aftermarket cats, and leaking piping. After reading tons of threads on exhaust options I decided on buying parts and re using from prior projects to build my own the best I can.

- Magnaflow spun cat
- thrush muffler
- assortment of mandrel bends
- Slee O2 sensor bungs
- Exh. couplers
- few clamps
- few ft. of exh. pipe (2 1/2")
- 2 sets exh. flanges
- Couple 6" grinder cut off discs

Overall around $400. I cut the exhaust off right after first weld joint in downpipe where two pipes connect. Took everything out but left the tailpipe (for now). Spent some time cutting mandrel bends, mocking up, and tack welding all the sections working my way back. I piped the cat with flanges at both end for easy dismantling. And yes I did go over the frame. Not the easiest without an actual mandrel bending machine. Oh well. So tomorrow I will be welding all the sections I made. Installing Slee O2 bungs. Weld downpipe section on. Weld in some hangers. AND fix those nasty rusted rear heater lines. Check out the pics below. I do have a couple questions for the exhaust pros:

1. Is it ok to locate the O2 sensors directly before and after the cat? See last pic for my location. I can also move the rear O2 back about a foot into next section if that is better for some reason

2. Should I have incorporated a flex pipe in the front maybe on downpipe? I see some people use them and some don't

 

[jamisobe]

Looks great! I love the mandrel bends and that spun cat. I didn't know spun cats where available with an angled exit like that.

I think the 02 bungs will be fine where you have them.

Too bad you couldn't do something with the Y off of the manifolds. Unfortunately that will probably be your pinch point with such a nice exhaust after it.

 

[scrowley]

Thanks. I only knew about that cat from some thread someone used the straight one and said they wished they made the angled one when they did theirs. So I tried it out. worked great. That thing is small. The Y pipe is in good shape but I will be back welding all the seams just in case.

 

[jamisobe]

The Y pipe is in good shape but I will be back welding all the seams just in case.

The bad thing about the stock Y is that it pinches the flow. It forces the exhaust pulses to have to squeeze against each other into the down pipe.

The EMS exhaust opened the Y and used a larger diameter down pipe which relieved the restriction:

This is how I ran mine together after the headers 2.25x2 into 3":

I had EMS add their curly pipe over the frame after this collector.

 

[Koffer]

looks great , now you just need to taking care of those weeping rear heater lines before they let go :whoops:

 

[scrowley]

Those are going today for sure. Just going to run heater hose instead and leave the old lines there. They didn't leak to I start aggravating the area. Better now than later.

 

[scrowley]

Custom Exhaust with Pics

Well I finished it the exhaust up today. That was a lot of work for sure. Glad its over. I also repaced my rear heater hoses with silicone hose. Overall I am happy with the turn out. It sounds great!! Not too loud, not to quiet. I will still be adding one more hanger, and header wrap in a few areas (by heater hoses, and over the frame area). Check out pics

 

[kbahus]

Looks great! This is exactly what I need to do with mine some day, I still might run into problems with dual cats and making that over the axle bend though. Stupid emissions laws.......

 

[scrowley]

Nice work on the collector on your exhaust. The EMS one is very nice.

The bad thing about the stock Y is that it pinches the flow. It forces the exhaust pulses to have to squeeze against each other into the down pipe.

The EMS exhaust opened the Y and used a larger diameter down pipe which relieved the restriction:


This is how I ran mine together after the headers 2.25x2 into 3":


I had EMS add their curly pipe over the frame after this collector.

 

[jamisobe]

Nice job on your exhaust! It looks great.

 

[scrowley]

Drove the truck around a bit today and it runs sooooo much better. smoother idle, more power overall, smoother through rpms. Glad I have this one under the belt. Next oil pan gaskets or/and rear mail seal leak fix

 

[scrowley]

Gave the exhaust a finishing touch with a little bit of header wrap in the tight spot over the frame.

 

[Tapage]

pretty nice .. did you ever consider using slip on sections instead of regular mandrel and weld .?

 

[scrowley]

I didnt want to have more possible leak points on the exhaust. Plus I dont think there is enough room to use slip joints. It was hard enough to get the over the frame part perfect so there was no rubbing or banging around welding it together. Also to make it easy to take apart with simple flanges.

 

[sneezy]

That looks like an awesome project. I too have been living with the P0420. PO took out the cat and replaced it with a muffler. I hate the sound of it and would like to get rid of the CIL. Have you done exhaust work before? Trying to figure out how hard it would be to myself.

 

[scrowley]

I have done exhaust repairs over the years but never just bought mandrel bends and fabbed one up. It was fun. Welding skills are key. And Time.

 

[Otamiway]

Nice system. How much miles have you put on it so far?? Any CEL??

Cheers
Stu

 

[scrowley]

Thanks, I have put about 75 miles on it so far. no check engine light..... knock on wood.

 

[Otamiway]

Thanks, I have put about 75 miles on it so far. no check engine light..... knock on wood.

Excellent...good job again

 

[Wagnerwerks]

That looks fantastic. Nice job!