I just got done doing mine on Friday. I went with a Magnaflow cat back that uses factory hangers. I had to sawzall out the stock mid muffler due to the rust. i got the clamp off just fine, but that muffler would not budge. I soaked it with WD-40 and hammered on it for 15 minutes before i threw in the rag and just cut it out. I have no need for the stock muffler, so it was no big loss to me. After that it was pretty simple, with the exception of the driver side add in hanger (for dual rear exits). just piece it together as the diagram shows and use the stock hangers and your set. it took me about 2 hours with nothing more than jack and stands, ratchet wrench, regular wrench, screwdriver and a can of WD-40. Oh, and the sawzall to remove the stock exhaust.

best of luck

 

I've got a sawzall, if needed but won't cut anything until I know it can be cut (not needed for new). My exhaust is a passenger side, behind tire, dual pipe exit so I won't have the additional hanger install.

Doesn't the pipe coming out the front of the old muffler overlap the front pipe coming to it and then a clamp holding it on? If so and you cut the old muffler off, you still have to deal with that overlapping pipe right?

 

On my kit (again I have an 07) the magnaflow muffler replaces the mid muffler on the stock exhaust. I couldn't get the stock mid muffler off the pipe coming from the front muffler (rusted solid), so I simply cut it right before the stock mid muffler slip coupling. So the "overlap" that you are referring to (at least on my exhaust) is simply the flange/slip coupling on the muffler itself and there was no problem. the new exhaust sits approx 1" farther towards the front of the truck than the stock setup, but the hangers had enough tolerance to allow that with no problems. I made sure of that before breaking out the sawzall.

nateroach

 

You'll do fine greg. Just have some patience and a little faith in yourself. Take it slow and steady and follow the directions. Just take it one thing at a time. Make sure to lay it all out and put everything where it needs to go on the ground first, get a picture in your mind and go to it. Make sure to take some pics for a possible diy for the forum.

 

I have NEVER not welded an exhaust system on. But I've been a hack welder since I was about 13 and got put to work summers and vacations in the shop my pop was foreman at and owned a small part of.

However, I got a friend I've played golf with on occasion who asked me if I'd be available to help him install a Flowmaster bolt on, cat-back kit. This guy is a total geek with no aptitude for tools. I never got a call on the sunday he set aside to do it and that night he sent me an email thanking me for being available but he was able to do it himself with no problem.
If this guy can do it, you can, and probably with a blindfold on...

 

Okay, so you guys that cut the muffler off, cut it at the edge of where the overlap ends instead of approximately where the front pipe would end inside of the overlapping pipe? Makes sense but I guess you gotta be sure you still have enough pipe left to get the new one on and it still fit. I know Gibson recommends a 2" overlap so that has to be taken into account too. Maybe, while I'm waiting for the new system to get here, I'll crawl under and see what I have to work with. In my old age, I'm learning to try and draw the line, in advance, between too much headache to try and save a buck and just opening up the wallet and let a professional do it right. It's about time for a service and tire rotation anyway so I could just get it all done at once.

 

Hammer, thanks for the words of encouragement (I think - LOL). I really don't think I'd have any trouble doing the install. I've reviewed the instructions and it looks straightforward enough. I think I can persuade all of the old parts off as well. It's just that first connection between the muffler and the front pipe I'm concerned about getting loose.

 

I did mine laying in the driveway, but mine was only about a year old. It came apart with a rubber mallet and a little wiggling. No cutting. I used white spray grease on my grommets. Works a little better. Took me under 1.5hrs to remove my stock and install my Magnaflow cat-back with dual pipes out the rear. On an older rig, you might want to spray the pipe joints with PB Blaster. It works better than WD-40 for this kind of stuff.

 

If you have a completely cat back system it doesn't matter where you cut the stock exhaust. I took mine off without cutting. I had a lift and a torch which made it a lot easier to pull the old one out but you should be fine. Spray the old exhaust with pb blaster then take a wire brush to it. If it doesn't come off you can buy a propane torch at lowes/home depot or just cut it.

 

I'm gonna go get some PB Blaster tomorrow and start pre-treating.

Below is the link to my install instructions. Notice the part, in the diagram, where it says not to remove (and I assume cutaway too much of) the pipe leading from the cat to the muffler. So, I'm not sure I follow you on not mattering where I cut the stock exhaust. I need to leave enough pipe to attach the new muffler and have everything fit properly from there on back, right?

We don't have too much of a rust problem or road salt issue around here but the truck is going on 6 years old. So, I'll see how it goes.

http://gibson.iwebcat.com/imgVD/GIB/6523.pdf