Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy Silverado and GMC Sierra Exhaust System Questions



  • obyoneobyone Posts: 8,065
    While under there checking for the leak make sure you check the connections BEFORE the muffler. Also check the O2 sensors, sometimes these exhaust guys while banging around under the truck bang one too many things.
  • I have a 2008 GMC Duramax 6.6 LLM and I want to do something with my exhaust and was wondering what would happen if I were to cut out my cat and straight pipe it from the turbo back. I have recieved several different answers when I ask what it will do to my truck. I am not worried about the warranty, unless it will cause damage, anyone that can give me a straight answer will be greatly appreciated, also if it wont hurt my truck, how much louder will it make it.
  • manombomanombo Posts: 1
    I have the same problem with my 2002 Silverado 1500. I developed an exhaust leak on the driver side and when I looked to check it out, I thought the back two bolts had fallen out. I went to the dealer to get replacements, but the were out of stock (which I thought was odd). When the special order came in they were different. The new ones had a larger head. Now the bad part... When I attempted to install the new bolts I found the old bolts had actually broken off in the head. Before I tear my cylinder head off the truck, does anyone know if there has been a recall on these?
  • akjbmwakjbmw Posts: 231
    Do some checking on what your local requirements for smog checks are/will be.
    I understand that there will be a smog check required here for my '07.5 LMM starting next year.
    The previous owner went to an aftermarket exhaust from the DPF back that wont affect the test. There are folks at the site who have done and reported on multiple combinations of exhaust mods for the various Duramax generations.
    I am inclined to believe that it is an aesthetic thing 'cause I REALLY don't see ever reaching the break-even point on the ROI. I think it would be a LOT more miles than I will put on it. Even considering that I will be pulling a trailer most of them.
    Yes, I like the exhaust sound but would not consider spending for the conversion. Also, I have no idea what the original exhaust sounded like.
  • i have a 2002 chevy silverado. i already have dual exhausts on it. i have a muffler and a cat. im taking the muffler off and putting in a y pie. will doing that mess anything up with the truck. or will every thing stay the same but it will just be louder?
  • obyoneobyone Posts: 8,065
    When you state dual exhausts I'm assuming true duals from the exhaust manifold to the tailpipe. Installing a Y pipe you're converting the dual setup to a dual in/ single out exhaust? If this is the case, it probably won't be louder and with more restriction you'll probably get better lowend.
  • nolonger8nolonger8 Posts: 1
    I have a 2004 2500hd with 30000 miles. i have been fighting with gm for 2 years on this issue right after the 3 year warranty my driver side went, they did under good will, 2 months later my passanger side went they would not honor it. now a year later my driver side is bad again. Im getting now where< i dont like spending 1000 every 8 months or so on this, is ther a recall or is this just super poor product?
  • iv got a 01 sierra 4.8 293 it has a single in dual out flowmaster 40 series and turn downs sounds great at low rpms but not past 2 grand. wonderin what would really make it roar at low and higher rpms?? also thinkn bout runnin a y-pipe then 2 single-in single-out flowmaster super 40 series?? let me know what u think and or any other systems u think or know sounds jus badass. thanks
  • obyoneobyone Posts: 8,065
    Cheapest would be to cut out the flowmaster and install a glass pack. Better yet skip the glass pack and weld a straight pipe in it's place. ;)
  • i have a 95 gmc with the 350 tbi motor, i have flowtech headers and then 2.5" pipe running all the way back with a h-pipe from flowmaster right after the headers and no cats with two super 44series and then it cuts out right after the rear axle to keep it hidden with no tips, its got a great low, high horsepower sound with no rasping at all and everyone that hears it seams to like it and yes it still is loud but sounds good
  • Okay now I'm confused I've done dual exhausts on several vehicles and this one has stumped me. I'm Running 2.5 inch Duals from the Manifolds back. I'm Using Holly RedHot glasspacks on each side. With the vehicle in park reved up to even 4k the trusk has a nice purr not overly loud but just enough for the good dual sound. I put this thing on the road yesterday and MASHED the pedal to see what it would do. The minute the engine broke 2500 RPM this thing sounded like it had NO exhaust whatsoever. I pulled the glass packs to see if i had one in backwards cause they weren't marked for easy installation and i've taken them off two or three times while tweaking the pips to make sure they fit perfect. The glass packs were installed properly. I Also noticed i have a MEAN tick in the donut gasket on the passenger side so i pulled the pipe at the manifold and checked the donut ring. it looks fine and seals properly to the naked eye. Both rings got replaced when i put the duals on so i know there is no wear in them and this was the trucks first run. ANYONE got any ideas. I'm stuck as to why this things gets so loud at higher rpms but only under load. Oxygen sensor reading show normal at idle and it never kicks the S.E.S. light on so i dont think its bad burn. The passenger side has a little funky smell to it when first running but i think that might be cause the truck hasn't run in like 7 months and it was running lean a little rich while the computer was resetting. (battery has been out for the whole 7 months so computer had to reset)
  • hi i have a 2007 shortbox reg cab 2wd sierra(new body style) and ive intstalled tru duals with glass packs. sounds like the garbage i thru out last night. i was wondering does anyone know how to bypass the o2sensor and co sensors on either side of the cat. any info would be great thanks!!
  • I just purchased a 1996 chevy tahoe 4WD, and we have changed the oil. it still had lots of exhaust smoke, but less than it did before the oil change. After maybe 20 minutes of driving,there is always white smoke and fumes. please let me know what is going on. :(
  • obyoneobyone Posts: 8,065
    edited April 2010
    White smoke is not good. Usually indicates a blown head gasket. The reason there is less of it after the oil change is because the new oil has less coolant mixed in with it.
  • glock75glock75 Posts: 1
    Kommeat, I have a gmc 3500 with a pass side leak that sounds like the doghnut did u fix urs and if so what was it mines also a tick. Thanx
  • I have a 2004 gmc sierra 3500 with a 6.0 gasoline engine and just got a new long tube headers for it but don&#146;t know how to do the exhaust design and I have a borla muffler so dose any one have any useful ideas I mean should I make it with one in put and two out puts or the opposite or two out and two in and what pipe should I use Y pipe, X pipe or H pipe what is the best to get the most power and an aggressive truck sound.

    :confuse: :confuse: :confuse: :confuse:
  • durmax07durmax07 Posts: 1
    We just traded a 2002 Chevy Silverado 1500 HD with the 6.0L and 4:10 rear gears. Back in March 10 I heard the exhaust leak and thought it was the exhaust gaskets, however it was the manifold bolts. Only 2 bolt on each side were holding the manifold on. I got lucky and the mechanic was able to get them out without pulling the heads. Cost $1200.00
  • obyoneobyone Posts: 8,065
    $1200 to tighten the exhaust manifold bolts?
  • davejrdavejr Posts: 1
    I took my truck into the dealer yesterday to have the exhaust manifold replaced. This is after I had been complaining for months about a leak and the noise it was making. And by the way, at 50,000 miles the dealer replaced the cam and lifters becuase they had worn to the point that the engine was making strange noises. This will be my last American made vehicle. Should have stayed with my Nissans, Toyotas and Hondas......Out 360,000 miles on my last Nissan before the timing change stretched and began to run rough. In 70,000 miles this GMC has spent more time in and out of dealerships than it has on the road.
Sign In or Register to comment.