its the wild west. with no emission testing its cheaper to throw out the exhaust and delete it than to fix it properly. See it everyday on the new diesels that de-rate the engine when scr and dpf problems are ignored. SAD

 

You have a very good point there. Around here, Most kids and even the older crowds have 4x4 diesel trucks with fat offset wheels , "rolling coal" consistently lol. It's just the culture I guess, I prefer the GM 350's and 454's myself.

So with deleting does that mean just cut everything off and run straight pipe? I don't like excessively loud exhaust, I prefer a deep rumble like a magnaflow or borla.

Also, had a buddy do the rag test over the muffler, I did find the leak, it is in the "doughnut" on the flange between the manifold itself and the forward most cat. It appears to secure one end of the cat to the manifold.
This explains the sounds coming from under the cab, I will go to oriellys today and just write down the codes from their reader and get em posted to confirm all this I hope lol.

What would you suggest easiest /cheapest possibly DIY fix for that ?

I was looking into O2 simulators , to fool the rear O2 sensors so my computer is giving the correct air/fuel ratio. I know fuel mileage is suffering , a little worse than it should be . I feel like this would be a temp fix, to get the computer straight and the check engine light off .

Just a thought, will give an update today, much appreciated 👍😁

 

 

7 and 4 it looks like are duplicates , took some live data snap shots also.

 

This is what I've been able to piece together with research, tell me if I'm wrong /right.

It seems like both O2 sensors, behind the cats, closest to the engine, are faulty . It adds up with the codes , and the two sensors in the rear, after the cats, are getting a bad reading because of that, which is messing with my pcm with fuel and whatnot. Also the heater is out on both sensors in the front, which explains the engines slow warm up speed , so I'm guessing two O2 sensors need replaced , probably all 4,
I think I'm going to go with the O2 simulators with the honeycomb in the tip, just replace all 4 with that, any thoughts ??
Later on I can pay to have the **** actually repaired and welded proper

 

Second thought , should probably replace the two O2 sensors behind the cat with factory originals that have the heaters built in. That way the heater code is gone and the engine warms up properly.

Then, replace the two rear O2 sensors with the simulators that have the honeycomb in the tip. I feel like this will correct everything and bypass the readings in the rear, because with the hole in the cat, I'm going to have bad exhaust exit readings until I get them replaced or just chopped off.
I feel the simulators would satisfy both of those scenarios

 

the heaters have a fuse...make sure its not blown.

 

Why not just replace the two o2's; sounds like the cats are ok and don't need removal.

 

Fuse is good, located it under the hood, #21 a 20 amp fuse labeled ENG 1 .

I'm going to repair that hole first and take it from there 👍 it's weird both front sensors read unresponsive, while the voltage on them seems correct. The rear sensor on bank 2 has the P0138 code, high voltage, it's reading 1.075, which is high and indicates a lack of oxygen and excessive fuel at the sensor. There's a few things to check there, but I will get the obvious leak fixed first. See what happens will post updates thanks again
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1. Performance Symptoms:
   

• Reduced power/acceleration (especially uphill)
  
• Poor fuel economy
  
• Sulfur/rotten egg smell from exhaust
  
• Excessive heat under vehicle
  

1. Diagnostic Steps:
   

• Check for P0420/P0430 trouble codes
  
• Perform backpressure test (should be <1.5 psi at idle, <3 psi at 2500 RPM)
  
• Inspect for physical damage or rattling sounds (broken honeycomb)
  

Your Options:

1. OEM Replacement: Most reliable but expensive ($800-$2000)
   
2. Aftermarket Catalytic: More affordable ($300-$800), ensure CARB compliance if needed
   
3. Test Pipe (Off-Road Only): Not street legal, requires tuning to prevent CEL
   

Pro Tip: Before replacing, verify your oxygen sensors are functioning properly - bad sensors often mimic converter failure. We carry direct-fit catalytic assemblies that include new gaskets and hardware for leak-free installation.