Aftermarket Catalytic Converter

[laminarflow]

I’ve got a 2015 GMC Sierra 1500 (5.3) with 165K KM. Check engine light is on and it’s the catalytic converter. Just got off the phone with GM Parts: quoted $3672 CAD for a new OEM cat -just the part (y-pipe - 3 cats). So that’s not going to happen. This truck has become a money pit in the past 12 months and I need to reign-in the costs.

 

A few questions:

 

1) Aftermarket cats are about 1/2 the price. Is there a brand you guys recommend … like Magnaflow? 
 

2) When the vehicle throws a code (for cats), typically which cat is it? MagnaFlow also sells the third cat for about $400.

 

3) Any other options? Thought about deleting the cats altogether, but then I’ll need to get the truck tuned. 
 

4) Aftermarket cats should meet or exceed OEM specs - it won’t keep throwing codes will it?
 

Thanks guys! 

Edited December 22, 2022 by laminarflow

[CamGTP]

P0420 is drivers side.

 

P0430 is passenger side.

 

Some aftermarket cats work okay and some don't, it's such a toss up nowadays with product quality. Hard to say if the aftermarket part you buy works without a hitch.

 

If the truck isn't down on power or anything you could just run it as is too. The light will just stay on and the remote start won't work anymore. Could also get a cheap handheld OBD2 scanner and keep resetting the light, might take a while for it to keep coming back.

Edited December 22, 2022 by CamGTP

[laminarflow]

Thanks Cameron. The third cat isn't associated with error codes - correct? From what I've read, it was only added to ensure the vehicle passed emission standards in CA.

[CamGTP]

Correct, the 3rd cat is not monitored by the computer.

[laminarflow]

7 minutes ago, CamGTP said:

P0420 is drivers side.

 

P0430 is passenger side.

 

Some aftermarket cats work okay and some don't, it's such a toss up nowadays with product quality. Hard to say if the aftermarket part you buy works without a hitch.

 

If the truck isn't down on power or anything you could just run it as is too. The light will just stay on and the remote start won't work anymore. Could also get a cheap handheld OBD2 scanner and keep resetting the light, might take a while for it to keep coming back.

 

I have been driving with it in this state for a while. Takes 2-3 days for the code to return. Sometimes the throttle can be a bit mushy/vague which is a symptom of cat issues. The truck is otherwise in immaculate condition; just been an expensive year (new AC condenser, new rad, transmission rebuilt ... now this). 

[movario]

There are aftermarket cats for around 500$ (for example walker). Those are the complete Y-unit with all cats. I don't know about workshop prices in your country, but it's around 1h of work to change.

I would go with that.

 

What are the fault codes? What exactly is broken about the cats? If you have a leaking injector, the new cats will also go bad quickly.