Yea it's a federal 😂. But imo a single cat for an almost 6 liter V8 that guzzles gas is not acceptable.

 

They flow enough to more than merely adequate to the task.....

 

Ok so I have good and bad news.
Good news is that after replacing the fuse and swapping the asd and horn relay the 20amp in fact did not blow after 35 miles of highway and city driving. Neither did the truck try to stall/lose power

The bad news is that the check engine light did not come on. 😬 No sensor short, no catalyst efficiency below normal, no evap system leak, no nothing.

This has me worried something else is horribly wrong with the truck, unless o2 sensors have a break-in period 🤷

 

How is no check engine light bad? Keep driving it and report back if anything comes up.

 

I have no catalytic converter, if the sensors are working properly I should be getting the "catalyst efficiency below normal" code. Maybe it'll come eventually

 

It will likely take the PCM a couple drive cycles to figure that one out. Just drive it.

 

So update on the current situation (I have driven 210 miles since the last post):
o2 sensor heater fuse somehow someway hasn't blown yet (remember all I did was swap the horn and ASD relay)
I still haven't gotten a code for either the o2 heater short or the catalyst efficiency below normal.
One strange thing that doesn't make sense is I have no check engine light anymore when my evap codes show up, they are there and show up when I scan for codes but the engine light isn't on, but it does do the "flash" cycle when turning on the ignition so it isn't burnt out.

This has been a weird situation for sure 😂