Aftermarket Headers and Y-Pipe without Cats

[WinnipegSilverado]

Hey Everyone, 

 

I wanted to add some Headers to the truck and was looking at these ones. My question is, without cats the CEL will obviously be thrown. What tuning options exist currently to disable that?

 

Thanks so much!

 

Headers

https://speed-engineering.com/collections/2019-2024-silverado-sierra-suv-exhaust/products/silverado-sierra-1-7-8-longtube-headers-2019-2024

Y-Pipe

https://speed-engineering.com/collections/2019-2024-silverado-sierra-suv-exhaust/products/silverado-sierra-y-pipe-2019-2024-5-3l-6-2l-truck-suv

 

 

[newdude]

24 minutes ago, WinnipegSilverado said:

Hey Everyone, 

 

I wanted to add some Headers to the truck and was looking at these ones. My question is, without cats the CEL will obviously be thrown. What tuning options exist currently to disable that?

 

Thanks so much!

 

Headers

https://speed-engineering.com/collections/2019-2024-silverado-sierra-suv-exhaust/products/silverado-sierra-1-7-8-longtube-headers-2019-2024

Y-Pipe

https://speed-engineering.com/collections/2019-2024-silverado-sierra-suv-exhaust/products/silverado-sierra-y-pipe-2019-2024-5-3l-6-2l-truck-suv

 

 

 

 

Its all going to depend on what year truck you have.  

 

That being said, year?  Make?  Model?  You've linked the y-pipes but left out the details on what vehicle you are trying to put this on.  

[WinnipegSilverado]

That might help eh! 

 

2023 Silverado 5.3 RST

 

Current mods

Intake

AWE Exhaust

3/5 lowering kit

[richard wysong]

Here in the states it is a Federal crime to modify the exhaust before and including the cats. No inspections up there?

[WinnipegSilverado]

nope

[newdude]

44 minutes ago, WinnipegSilverado said:

That might help eh! 

 

2023 Silverado 5.3 RST

 

Current mods

Intake

AWE Exhaust

3/5 lowering kit

 

 

HP Tuners is the only outlet for tuning.  Not sure how it would be done with them being you are in Canada though as HP is in the states.  

 

ECM is required to be unlocked or replaced with an unlocked unit on the 2022.5-current Global B trucks/SUVs with V8.    

 

The E90 ECM service - GM E90 ECM Service (Global B) – HP Tuners

 

The TCM service if you plan for full ECM and TCM tuning - GM T93 TCM Service (Global B) – HP Tuners

 

Then you will need to find a tuning shop who can tune everything afterwards.  12 credits are required to access both modules from the tuning shop so there's another $600.  

 

 

 

 

[Silverado4x4]

All that work and money for just about zero gains with headers unless you spend most of your time at WOT. 

Edited April 10, 2025 by Silverado4x4

[CamGTP]

Plus HP Tuners can't fully delete emissions anymore. There will be background tables we can't access anymore. Sure the check engine light might stay off but there is likely cat tests and rear o2 sensor tests that will stay active in the background.

 

Headers to me aren't worth it when it going to cost you so much just to tune it.

[WinnipegSilverado]

Thanks for all the insight! Youre totally right its not worth the cost to delete the cats. I was just looking to get a different sound out of the truck and thought this would be something to try. I could always just add cats to their Y-Pipe if I really wanted to do it and not tune the truck. 

[newdude]

34 minutes ago, WinnipegSilverado said:

Thanks for all the insight! Youre totally right its not worth the cost to delete the cats. I was just looking to get a different sound out of the truck and thought this would be something to try. I could always just add cats to their Y-Pipe if I really wanted to do it and not tune the truck. 

 

 

You'd likely need tuning with aftermarket cats as well.  Stock ECM knows what data its looking for with the OE sensors and if its CARB or EPA/Federal cats.  You could install and may run into cat efficiency codes on a stock tune truck.

 

IMO, I'd start with post cat mods first.  Catback like Corsa, Borla, MBRP, etc.  Or a full muffler delete.  

 

 

[Silverado4x4]

5 minutes ago, newdude said:

 

 

You'd likely need tuning with aftermarket cats as well.  Stock ECM knows what data its looking for with the OE sensors and if its CARB or EPA/Federal cats.  You could install and may run into cat efficiency codes on a stock tune truck.

 

IMO, I'd start with post cat mods first.  Catback like Corsa, Borla, MBRP, etc.  Or a full muffler delete.  

 

 

What he said. Even the stock cats are high flow.

[typhoon186]

Not much if any gain removing or replacing the cats.  When you sell the truck, no cats can become a big issue.  

 

I can't rember the name, but there is a plug-in that mimics a cat and tricks the ecm to thining it's there and ok.  Not sure if they will work on these trucks.

[e.texerado]

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html