Kooks y pipe problems

[m1c]

I have a 2018 Sierra RCSB 5.3, 4x4 that I added Kooks 1-7/8 long tube headers and green catted y pipe too. I'm having trouble with the y pipe reaching the Borla ATAK catback. It seems to be a couple inches too short. Has anyone else had this issue?

[ftwhite]

I had a similar problem getting the kooks ypipe to connect. The ball joint just wouldn't tighten up enough to close the gap and not leak. I had a muffler shop weld on a flange joint instead. Not as flexible, but there is another flex point downstream, and no problems over 10k miles so far.

[3tspapat]

Longer exhaust hangers/bushings should should allow you to move the catback frontwards enough to get it to fit.

[M1ck3y]

Yup, I have that problem. I contacted kooks and my understanding is that I have over tightened the y-pipe to header connections.

 

I've been meaning to take a rubber mallet to the y-pipe to break the connection (ball/socket joint). Bolt up the cat back first and then "snug" it back up to the headers. Ball/socket connection doesn't need much torque (just enough to hold it in place); heat from the exhaust will do the rest.

Edited May 3, 2022 by M1ck3y

[m1c]

Thanks, for the suggestion.

 

My y pipe was nearly 3" short. I slid the mid-pipe from the catback forward and had to pull it out of the hangar to reach. It's a little jury rigged at the moment. I was working with Kook's tech support, but they turned me over to the CEO who suggested cutting it up and putting a 3" wide clamp there. Not thrilled about that, but not bashing them either.  I think I've decided to put a resonator there before the muffler anyway to cut back on the sound.

[m1c]

My y pipe was that short before i even snugged up the ball joints to the headers. I'm a little disappointed in the customer service for such a premium priced product thus far.

[M1ck3y]

Yeah I hear you, I'm just quoting what Kooks said to me; Mine might be just as short as your's is. I ended up jamming a 2x6 bewteen the axle and the muffler to force it forward and bolt it up 

 

I have a borla 40004s muffler I might try and fit in there. 

 

In hindsight I should have gone with ARH.

Edited May 3, 2022 by M1ck3y

[m1c]

I tried ratchet strapping it together from the exhaust mount to the transmission support, but I didn't like it pulling the exhaust tips under the truck. 

 

The worst part is it caused me to cancel my date with the tuner, and now I can't get on the schedule for 2-3 weeks. 

[m1c]

Now it sounds like something is loose in the drivers side greencat. Metallic rattling noise... any ideas? Thanks!

[M1ck3y]

3 hours ago, m1c said:

Now it sounds like something is loose in the drivers side greencat. Metallic rattling noise... any ideas? Thanks!

 

I know on mine when the exhaust is cold the clamp's at the ball/socket joint will sit loose, and can make noise if you hit on it. Other than that... it could be the substrate is loose in the cat 

[m1c]

The rattle is definitely coming from the cats (now both sides). I have checked for loose connections and anything touching the headers. I can stop the rattle by touching something to the cats while it's rattling. Touching anywhere along the headers and primaries has no effect. Sent a video to Kooks at their request this was what they said to check. 

 

Regarding the y pipe, I'm exceptionally disappointed in the craftsmanship and customer service of Kooks. I received no other responses from them on these issues. I slid the mid pipe forward and removed it from the hanger mount just so the ball and socket would seat well enough to clamp together. I decided to have the y pipe and the mid-pipe to the cat back cut and a Vibrant resonator welded in place. I can't believe how much of a difference the resonator made on the sound of the headers! Love the sound of this combination. 

 

Thanks all for your help!