New catalytic converter. Less power; more noise.

That’s effectively what’s happening. It takes about 50 miles for the ECU to run through adaptations.

 

So, I came down with COVID. I don't know if it's the rumored strain all over mainstream media. Regardless, it has been really awful.

Whenever I get sick, I make it a point to get sunlight. Usually, I will sit in front of my dining room window. When I gain enough strength, I tend to go for a drive. My thinking is this is a great way to get sunlight without infecting anyone else.

I bring that up because I have been driving around lately in order to get some sunlight. This has given me a chance to monitor my truck's performance.

The noise generated by my exhaust system has mellowed out a little bit. Not much; but the difference is audible.

In terms of acceleration, it seems like the truck feels how it used to feel.

All of that being said, albeit unscientific, I feel confident saying that anyone who looks into a Magnaflow catalytic converter should expect diminished acceleration and excessive exhaust noise for at least 50 miles. I realize this is all anecdotal but in the absence of a dyno this is about as good as we can do.