Scarsman
Sponsor
- Messages
- 1,561
- Location
- Monroe, WA
Well, I have been having a horrible and very annoying rattle coming from inside my stock muffler for several months. 
Also, recently I noticed that the rear bolt on the driver's side exhaust manifold was broken off. I know this is an inevitable issue for the 6.0, so I had planned to replace the bolts before they broke, but had not yet gotten around to doing so. :gaah:
I found the broken bolt issue because my CEL came on and I started having a rough idle/almost stalling issue. I plugged in my tuner and found there were a few codes:
:whaa: They were all related to the pre-cat o2 sensor, lean condition, random misfire, fuel issue, all for bank one. The driver's side. Turns out the broken bolt on the manifold was letting the manifold leak, causing the o2 sensor to send out screwy signals, which messed with the idle and everything else, and threw all the codes.
So, for the manifold issue I ordered an ARP stainless stud kit, part #4341301, and AC Delco manifold gaskets, part #12617944. I removed the remaining bolts, which came out pretty easily. Then pulled the manifold out of the way. The bolt had broken just barely below the head, so once the manifold was out of the way there was about 3/8" of the bolt sticking out of the head. Crossing my fingers I grabbed some vice grips and prayed that it would come out. The alternative would be to first try heating it, and next would be trying to weld a nut to it. This would be very difficult due to it being so close to the firewall. And if that failed, the head would have to come off. :eek Fortunately, the planets aligned perfectly and it came out. It was slow, and took about 20 minutes to thread it out, and my hands are bruised and battered, but out it came. :yippee I coated the studs with some good anti-sieze and threaded them into the head. The ARP studs have a allen socket in the end of them, making it easy to get them snugged in well. Slipped the new gasket on the studs, popped the manifold back on, and torqued it back down. I did not get any pictures of the process, but it is pretty simple. It doesn't look any different than before, other than having shiny stainless studs and nuts in place of the old rusty bolt heads.
I also put in a new Bosch o2 sensor, part #15282. Not sure if the old one was still ok or not, but figured I might as well.
Then on to the rattling muffler. Here is what it has been sounding like:
[video=youtube;ckxj3pOoxyc]https://www.youtube.com/watch?v=ckxj3pOoxyc&index=7&list=UU7JRV4Q_dz39E1c6 9EQSMRg[/video]
I opted to go with the Flowmaster cat-back system, part #17376. This kit is no longer made, but there are still some out there. I ordered it from three places who had it in stock, only to have my money refunded when they did not have it. Finally found it at SK Speed in New York. They actually had two in stock! Part of the reason I went with this kit is because it is designed with a resonator to eliminate interior drone. I also did not want it to be too loud.
It arrived last week:
The stock system is dual in, then dual out into one tail pipe. It is all one piece from the mid-pipes back. I had to cut the tail pipe off of it to get it out from under the truck. Here it is minus the tail pipe:
The Flowmaster is dual-in to the resonator, and then single out into the muffler, and then the over the axle tailpipe, so three pieces in all. The resonator has the correct fitting and piping to hook up to the stock mid-pipes.
It comes with clamps for the stock slip joint at the mid pipe, the res-to-muffler joint, and the muffler to tail pipe joint. I chose to fully weld the resonator and muffler joint. I would have liked to also weld the tail pipe as well, but the only way to get it all in place then would be to remove the rear track bar and possibly even unhook the RR shock, and then jack the body WAY up from the axle. So I settled for the clamp.
Here is the welded joint with some high temp paint over the weld:
This is the clamp with hanger at the muffler to tail pipe joint:
The system comes with a gross, shiny, polished, chromy tip welded on the tail pipe that sticks out just under the bumper. :barf2::shame: Obviously that would never work on my truck. So, it got cut off back where the stock pipe ended, up inside where it wont get crushed.
A view looking forward. Sorry, I didn't notice it came out so blurry. I'll try and replace it with a better one.
And here is what it sounds like now. I wish I would have done a before sound clip, but I did not think about it at the time. But we all know what they sound like stock anyway.
[video=youtube;crFTNC-EB-0]https://www.youtube.com/watch?v=crFTNC-EB-0&index=1&list=UU7JRV4Q_dz39E1c69EQSMRg[/video]
It is just a bit louder than stock, but has a beefier sounding tone to it. Interior sound is just a tad more, but is not intrusive at all. And there is absolutely no drone at any speed or engine load.
So far about 40 miles and no codes or rough idel issues anymore. :horns:
Also, recently I noticed that the rear bolt on the driver's side exhaust manifold was broken off. I know this is an inevitable issue for the 6.0, so I had planned to replace the bolts before they broke, but had not yet gotten around to doing so. :gaah:I found the broken bolt issue because my CEL came on and I started having a rough idle/almost stalling issue. I plugged in my tuner and found there were a few codes:
:whaa: They were all related to the pre-cat o2 sensor, lean condition, random misfire, fuel issue, all for bank one. The driver's side. Turns out the broken bolt on the manifold was letting the manifold leak, causing the o2 sensor to send out screwy signals, which messed with the idle and everything else, and threw all the codes.
So, for the manifold issue I ordered an ARP stainless stud kit, part #4341301, and AC Delco manifold gaskets, part #12617944. I removed the remaining bolts, which came out pretty easily. Then pulled the manifold out of the way. The bolt had broken just barely below the head, so once the manifold was out of the way there was about 3/8" of the bolt sticking out of the head. Crossing my fingers I grabbed some vice grips and prayed that it would come out. The alternative would be to first try heating it, and next would be trying to weld a nut to it. This would be very difficult due to it being so close to the firewall. And if that failed, the head would have to come off. :eek Fortunately, the planets aligned perfectly and it came out. It was slow, and took about 20 minutes to thread it out, and my hands are bruised and battered, but out it came. :yippee I coated the studs with some good anti-sieze and threaded them into the head. The ARP studs have a allen socket in the end of them, making it easy to get them snugged in well. Slipped the new gasket on the studs, popped the manifold back on, and torqued it back down. I did not get any pictures of the process, but it is pretty simple. It doesn't look any different than before, other than having shiny stainless studs and nuts in place of the old rusty bolt heads.
I also put in a new Bosch o2 sensor, part #15282. Not sure if the old one was still ok or not, but figured I might as well.
Then on to the rattling muffler. Here is what it has been sounding like:
[video=youtube;ckxj3pOoxyc]https://www.youtube.com/watch?v=ckxj3pOoxyc&index=7&list=UU7JRV4Q_dz39E1c6 9EQSMRg[/video]
I opted to go with the Flowmaster cat-back system, part #17376. This kit is no longer made, but there are still some out there. I ordered it from three places who had it in stock, only to have my money refunded when they did not have it. Finally found it at SK Speed in New York. They actually had two in stock! Part of the reason I went with this kit is because it is designed with a resonator to eliminate interior drone. I also did not want it to be too loud.
It arrived last week:
The stock system is dual in, then dual out into one tail pipe. It is all one piece from the mid-pipes back. I had to cut the tail pipe off of it to get it out from under the truck. Here it is minus the tail pipe:
The Flowmaster is dual-in to the resonator, and then single out into the muffler, and then the over the axle tailpipe, so three pieces in all. The resonator has the correct fitting and piping to hook up to the stock mid-pipes.
It comes with clamps for the stock slip joint at the mid pipe, the res-to-muffler joint, and the muffler to tail pipe joint. I chose to fully weld the resonator and muffler joint. I would have liked to also weld the tail pipe as well, but the only way to get it all in place then would be to remove the rear track bar and possibly even unhook the RR shock, and then jack the body WAY up from the axle. So I settled for the clamp.
Here is the welded joint with some high temp paint over the weld:
This is the clamp with hanger at the muffler to tail pipe joint:
The system comes with a gross, shiny, polished, chromy tip welded on the tail pipe that sticks out just under the bumper. :barf2::shame: Obviously that would never work on my truck. So, it got cut off back where the stock pipe ended, up inside where it wont get crushed.
A view looking forward. Sorry, I didn't notice it came out so blurry. I'll try and replace it with a better one.
And here is what it sounds like now. I wish I would have done a before sound clip, but I did not think about it at the time. But we all know what they sound like stock anyway.
[video=youtube;crFTNC-EB-0]https://www.youtube.com/watch?v=crFTNC-EB-0&index=1&list=UU7JRV4Q_dz39E1c69EQSMRg[/video]
It is just a bit louder than stock, but has a beefier sounding tone to it. Interior sound is just a tad more, but is not intrusive at all. And there is absolutely no drone at any speed or engine load.
So far about 40 miles and no codes or rough idel issues anymore. :horns:
Last edited:
