H2 Exhaust replacement

[The_Mountain]

I need ideas on replacing my truck's exhaust. Here's the rundown:

I have a very minor exhaust header leak when it's cold (tick tick tick tick...; goes away after a few minutes of driving). Pretty sure that's just a gasket.
The cat pipes are getting pretty rusty downstream from the cats themselves (there might be one tiny leak on one of them; I saw what looked like a carbon streak).
The catback portion is really starting to go downhill; rusty pipes, several small holes in the muffler, a tin-rattling sound when cold (probably a broken baffle inside the muffler/resonator unit), occasional sensations like one or more hangers have broken allowing it to sway around.

I really don't want to spend a fortune for a Borla or Corsa system. I don't think either of the stock exhaust manifolds are themselves cracked. Should I bother replacing them with headers, or just get new gaskets installed? Would the potential cost increase be justified if I replace the cat pipes with "better" ones, or are the stock systems good enough and less expensive? For the catback portion, I would like just a bit more tone than the stock (and huge) muffler produces, but would prefer to keep the stock pipe routing if possible, and definitely want to retain the stock tailpipe exit location (nothing protruding below the rear bumper).

Overall, I'm not looking for any kind of performance increase specifically, but would like just a bit more rumble (I prefer the "turbo"/glasspack sound over the "Flowmaster" sound). I am looking to do this replacement without pouring huge amounts of money into it. If there are modifications I can make without adding significant cost, I'm open to them. I am fine with doing a parts-bin install (universal muffler from here, resonator from there, cats from those guys, gaskets from somewhere else etc).

 

[Big2dabank]

I run a set of Dynatech long tube Headers and a Flowmaster Exhaust. I had a cracked manifold and broken bolt and a busted cat, so I had to do something and decided the headers was the best route. However, I'm not sure if the kits are still available for the H2, as I did this over 4 years ago. I know another member (scarsman) went through this recently and I think he found the flow master exhaust locally and found some headers at a speed shop. He may chime in on this thread wit more info.

Here is what I have if you can find it...

 

[Scarsman]

I would definitely check your manifold bolts for the leak. The 6.0 is known for the rear manifold bolt heads breaking off. That's what happened to mine. Did find a local shop for long tube headers, but due to costs I have not done that yet. I replaced all my manifold bolts with ARP stainless studs and new gaskets.

I did go with a Flowmaster cat back system. It has awesome rumble, but no drone at all. However they are discontinued. I was able to find a place that still had one.

In the future though, I will be going with the custom long tube headers when money allows.

Sent from my SM-G900V using Tapatalk

 

[The_Mountain]

I'm grateful for the info so far. One other aspect I forgot to mention is that I may be swapping my current H2 for a different one based on what I've discovered about the truck since buying it (there are some options/configurations I would rather not have, as it turns out). I therefore don't want to put a ton of money into a custom "forever" exhaust system, but since I have to look at the cat pipes and headers, I am not married to installing a replacement stock exhaust either.


Edited to add, since this appears to matter to the exhaust companies: My truck is equipped with the dual-compressor rear air suspension.

 

[Big2dabank]

If it's the air suspension that bothers you, just swap in coils. Super easy and cheap. It might take 30 mins total.


Sent from my iPhone using Tapatalk

 

[The_Mountain]

If it's the air suspension that bothers you, just swap in coils. Super easy and cheap. It might take 30 mins total.


Sent from my iPhone using Tapatalk

It's not that it bothers me (though it does), but apparently many of the catback exhaust systems don't fit H2s with the air compressors.

 

[Renagade132]

Scarsman, What's the advantage of long tube headers, over the stock ones? They have to be made custom?

 

[The_Mountain]

Scarsman, What's the advantage of long tube headers, over the stock ones? They have to be made custom?

Long-tube headers typically improve high-rpm performance, especially focusing on horsepower. You'll get a performance improvement, but on a low-RPM crawler like the Hummer you're not ever likely to realize the full performance potential. They're also often not emissions-compliant because they usually eliminate the catalytic converters and sometimes are missing fittings for things like O2 sensors etc. Many companies make model-specific headers to fit a wide range of vehicles, though you can have them custom-built if you want. Stock manifolds traditionally (in any application) are designed for ease of installation, sound mitigation, and low cost, and tend to be restrictive and not always well-matched to the engine exhaust ports. Plus, stock exhaust manifolds are usually cast iron, so they can crack over time, unlike headers which are usually steel tubing, and thus more flexible. Short-tube headers are a compromise, in that they flow better than stock manifolds and thus improve performance while still retaining all the emissions components, but tend to be louder, harder to install, and degrade access to the sides of the engine due to the extra tubing. A better solution for trucks like ours are "Tri-Y" headers which emphasize low to midrange RPM performance and torque, but retaining the cats can sometimes be problematic.

 

[Big2dabank]

I had cracked manifold and a busted cat, so I can only speak from the kit I have which is made by Dynatech. It has an option with the high flow cats and without, I chose the high flow cats which also has O2 sensors. I can feel a noticeable power gain across the entire RPM range and it gives the truck a high performance sound that just can't be achieved with just a cat back exhaust. I worked with a local LS motor performance shop to get a custom tune using an HP Tuner that helps round out the performance of my add ons to fullest extent possible. He only had a two wheel dyno, so we could not test all four wheels. So it was tested with the seat/butt dyno to dial everything in. Sure its slightly louder in the cab, but we are talking about an H2, not a lexus, so that doesn't bother me. In fact I get more road noise from my MT/s and the airflow through my cold air intake than I get from the exhaust. Is it worth the money, well thats a personal choice and I would not do it unless I had to replace the manifolds and cats anyway. Thats my 2 cents from my personal experience.

 

[flyday58]

Late to the thread, but my '04 had that exhaust tictictic when I bought it. All bolt heads were intact, but as soon as I tried to loosen them up to see if I could replace them with better bolts I snapped one off. Took it to a local shop and they found the manifold cracked and eroded where it was leaking. I just went back with a stock manifold but am still looking at replacing the entire exhaust with something better.

Truck has 149k on it and this was the left header. Right is fine.

 

[KTM640Dakar]

If the tic tic goes away when the engine warms up it is likely broken header bolts.

 

[The_Mountain]

If the tic tic goes away when the engine warms up it is likely broken header bolts.

It does go away after just a couple of minutes of running the motor. I checked the bolts, and as far as I can tell, all the bolts look intact. It might be that one of the manifolds (I'm pretty sure it's the left side, just like flyday58's) is warped or cracked slightly. It's almost inaudible if the windows are up, so it's not serious (yet). But since the rest of the exhaust is in such bad shape, I figure I can get this knocked out at the same time.

 

[DetroixH2]

TicTicTic eventually got worse - Now car sounds like S**T all the time

I had cracked manifold and a busted cat, so I can only speak from the kit I have which is made by Dynatech. It has an option with the high flow cats and without, I chose the high flow cats which also has O2 sensors. I can feel a noticeable power gain across the entire RPM range and it gives the truck a high performance sound that just can't be achieved with just a cat back exhaust. I worked with a local LS motor performance shop to get a custom tune using an HP Tuner that helps round out the performance of my add ons to fullest extent possible. He only had a two wheel dyno, so we could not test all four wheels. So it was tested with the seat/butt dyno to dial everything in. Sure its slightly louder in the cab, but we are talking about an H2, not a lexus, so that doesn't bother me. In fact I get more road noise from my MT/s and the airflow through my cold air intake than I get from the exhaust. Is it worth the money, well thats a personal choice and I would not do it unless I had to replace the manifolds and cats anyway. Thats my 2 cents from my personal experience.

No one in Detroit area seems to be able to fix this problem for me, except for the dealer which is so costly. When you say its "worth the money" - do you mind (and anyone else on this thread) giving me an estimate of what this kind of repair costs?
The dealer didnt give details just said its a "big job", so I didnt have them do it if they didnt have the courtesy to tell a woman what the details of the repair is.
There is definitely a leak in exhaust, probably a cracked manifold as with Big2dabank mentioned.
Basically I have been going broke replacing all the rusted out parts lately on my 2003 H2 that I now just want to fix this noise good enough to sell it - Sadly, as Ive loved it from the day it rolled off the assembly line... it was one of the first hundred made in 2002 and now only has 91k miles...but i cant afford the repairs any longer. So can you guys give me some knowledge about this exhaust repair so I can go out and find someone to fix it (that is not the rip-off dealership).
Thank you in advance for all your input.

 

[5gn-h3t]

Just replace the manifold with a new one. They are about $100 each on ebay. Brand new. They are not too bad to replace. However, if any of the manifold bolts are broken, or break, it can be really horrible to get them out. This is where time/money can add up real quick if it's at a dealer.

If your goal is to get rid of this thing, just sell it the way it is and don't worry about it. I doubt the $$$ and aggravation invested will get you much of a return when you sell.

 

[DetroixH2]

Just replace the manifold with a new one. They are about $100 each on ebay. Brand new. They are not too bad to replace. However, if any of the manifold bolts are broken, or break, it can be really horrible to get them out. This is where time/money can add up real quick if it's at a dealer.

If your goal is to get rid of this thing, just sell it the way it is and don't worry about it. I doubt the $$$ and aggravation invested will get you much of a return when you sell.

You think? I am sprucing up the body a little with regards to the rust and i replaced the front windshield... but that noise is VERY obvious when you turn it on and I just didnt want someone being so put off by it that they dont buy it. I dont know though, I think youre right about the $ and aggravation. Ive already spent a few thousand getting her ready to sell and that is without this exhaust.
I tried to get someone to change exhaust on the side but he too wanted $1000 to do as he said it is a pain to get to and he'd have to "take out the engine" to get to it...
Hmmmm - how's that sound to you?

 

[5gn-h3t]

You definitely DO NOT have to remove the engine. I've done this in my driveway.