I have put 3 cast iron exhaust manifolds on 2010 Colorado in it's life so far of 288,88 k miles, the cat converter is built right onto cast iron manifold. They are kind that like crack on that 2.9 motor, the last was on it. 2.5 yrs ago. Had donut gasket put in a yr ago . Now that colder. Make louder noise on startup. Like crack manifold an smell exhaust until warmup . Unless secondary air exhaust injecter valve on cold start ? I heard they worse cold , was lil over 800 install. But if this one's crack . The price has skyrocket . I told noway repair or weld , if end up get worse which I hope it not crack. Is there small possibility that can use jb weld compound ? The cracks always happen around converter where built on manifold

You can braze it. Not too hard. If it’s warped bad, you need to sand the warp out before brazing.

Jb weld probably wont last . Im sure if you take it to a weld shop they should be able to weld it.

Shop say in past . Noway can be welded a cast iron exhaust manifold the way it crack around converter that integrated on manifold , I let every one them crack go for months. An when it went . It so loud . I barely made it 8 miles home work an had tow, very expensive an after pandemic, price crazy on them . The thought If afford, a 4 the one, nope ! Maybe it not crack or last months if is, one last 6 mo, when crack , aluminum can be weld but they say not cast, an if so. No last

My buddies got the same truck but doesn’t fix anything. On his way here to jump in with me, I hear him coming about 1/4 mile away from inside the house. I go outside and guide him down the driveway like ground crew at an airport. When he drives and I jump in with him, I scan the ceiling & dash pretending to flip switches , flaps check OK were ready to take off…lol
The Otter

Wonder kind deal u get if it was crack manifold an got worse with that many miles on even Steven trade on another truck from dealer with minium payments ? Screwed bad ?

The check engine lite for cat converter, below efficiency threshold, code, has been on for year, just like other ones for California emission system. It means it not work right like other manifolds did same

At least three times I told ya what causes this.

That hard pack lake surface with snow, is smooth enough the plane don't upset when take off or land ?

I guess not. Buddies looking at a new truck….another Colorado. MBcooner has one, they look pretty slick.

They are slick.but man the price with inflation nowadays on new !! U could buy my house with price some pickups, crazy inflation ! Noway the new ones worth the money . I bought mine new in 2010. Now that truck probly close 40k. Over dbl plus 3-4 grand more . I don't like lot extra stuff on them. More wear out . To much plastic junk . Alright new an under warrantee but u better have some big $$$ bucks save up shop later on . The 2006 an year around then was not good Colorado engine head . Also I don't think most 5 cyl. We're of good design or trouble with in shop . Mine was good truck an lot use. 3 -4 yrs ago. Things start wear out with lot parts or components replace . 7 yrs almost bfore any trouble much all