2000 K3500 question

[Intragration]

I would think it unlikely that other things were tuned out. Sometimes cats get clogged, or people just don't like them, so they take them off and tune them out if necessary. You HAVE to tune them out if there's a post-cat O2 sensor and the cat is gone, at least if you want the CEL to remain off. You don't HAVE to tune other things out. Have you confirmed that the CEL lamp still works? It should go on during the pre-start light test.

 

[Brav302]

Yes, the CEL works. It comes on then goes off. Code reader shows no codes.

 

[454cid]

I read years ago that 2000 454s did not get the post cat o2 sensors. I'd bet it's supposed to have cats, though.

 

[Keeper]

Removing the cats on that truck will not throw codes and does not require a tune. Run it.

 

[Brav302]

Thanks for all the input. There definitely aren’t any rear O2 sensors. I don’t see any wiring for them either.

 

[packer0440]

It should have CATs. My 92 454 truck had one. Interestingly, however, they placed the cat after the muffler, closer the back of the exhaust. I have no idea what the impetus was to place it there. It is gone now, had no real effect on performance.

 

[b454rat]

I'll check mine that is a 2000, it's a big block truck, an HD so technically not a 1 ton. But I still say it had cats, someone took them off and just tucked the wires somewhere. Only thing that I've seen that wouldn't have cats is a medium duty truck, Kodiak, Top Kick type trucks.

 

[Schurkey]

The '97 service manual shows about fifteen different exhaust systems for the various models--single-cat, dual-cat, different models, different wheelbases, different GVW, Chassis-Cab models, etc.

Find the service manual for 2000 and see what it shows for your particular GVW and wheelbase, etc.

 

[andy396]

Thanks for all the input. There definitely aren’t any rear O2 sensors. I don’t see any wiring for them either.

I had a 2000 7.4L parts truck that I used to swap into my truck. I can further confirm 2000 had two cats and only upstream O2 sensors.