Hello,

I own a 2007 Hummer H3 Luxury (3.7 Inline 5) for which I had the Exhaust Manifold replaced in 2021. It started making a exhaust leak sound a couple weeks ago, the dealer states it has blown a hole in the exhaust. He explained that it is a common issue.
Wanted to seek some advice on what would be the best option moving forward?

1. Can the H3 run without catalytic converters? Was thinking of straight piping it if it would keep having this issue more frequently. I live in Michigan. What would be the consequences of running it without catalytic converter?
2. What experience do other owners have on replacing the Exhaust manifold

Any advice is appreciated.

Thank you!

 

I'm not taking on any legal woes by recommending any type of fed gov cheats...no way! lol!
Doesn't matter which state I lived in the fed epa gov rules trump em all.

 

Replacement of the Exhaust header can be done at home. Utube has some videos on it.

 

That was probably not the right question to ask lol. Was not aware that taking the Cats off was a major offence. I see many vehicles in Flint, Saginaw, Detroit area without them.

Appreciate the response!

Are there any better aftermarket designs as the dealer stated that the GM OEM Manifold has a design flaw?

 

Did he not tell you WHERE in the exhaust there's a hole?

Is it in the headpipe? in between the two cats? After the final cat?

 

Why on earth would you take your 16 year old truck to a dealer?????? Last place on earth to take a vehicle to for anything not covered by warranty.

Ask family, friends, co-workers for the name of a reputable local exhaust shop to take it for a look. I am NOT talking about any of the national exhaust chains, they all suck, use thin cheap pipe that will rot out in 2-3 years. Go to an exhaust specialist, the kind that does custom work on nice cars, race cars, hot rods etc...