Exhaust noisy while under load

The exhaust in my truck suddenly got loud when under load. Starts around 2k RPM in 2nd gear, goes away if I back off the gas even at the same RPM level as I upshift. Rev'ing the engine in neutral or with the clutch in sounds normal. No visible exhaust problems, and it's not rusty. I still need to crawl under and double check, but I would think a hole in the system would make it loud all the time, not just when under load.

Here's a video, at the very end I rev'd it a couple times with the clutch in for comparison.

Anyone have an idea what this might be caused by?

https://www.youtube.com/watch?v=chpI5vmeuVk

 

IDK? Sounds good to me!

 

I kinda like it too, but after it being quiet for 8 years (and no exhaust mods) it makes me wonder WTF happened.

I already routinely have to clear a P0430 code, so I'm really hoping there's not more wrong with the exhaust.

I'm also confused about what's different between load and no load.

It was "normal" on Sunday. Then Monday morning on the way to work it was loud.

 

It might be a heat shield that has rattled loose

 

This! Or one bent just enough to barely touch.

 

Yeah, I'll check that. I had a chunk of ice rattling against the frame last week. Just odd that it only happens when I'm accelerating. Speed doesn't seem to affect it, and the same RPM when the transmission is disengaged doesn't produce the noise.

 

How many miles? Maybe the cats are toast?

 

120k, and I'm thinking maybe the passenger side on is, or is going due to the P0430 - Catalytic Converter Inefficiency code I keep getting. I want to see if I can remove it and clean it out when the weather warms up. I've heard a couple ideas of soaking them in orange juice, or soapy water to dissolve build up.

 

Welp, took another look under there and the muffler is rotted out around the tip. The can's top lip has several holes along it, and around where the tip is attached.

Must have just rusted through Sunday night or something... It was fine during the day Sunday when I went to have the oil changed.

 

Does the muffler have baffles? Could be a lose one.

 

The tip that comes out behind the rear passenger side tire. So the back of the muffler, the top lip/roll/pinch weld is severely perforated, and there's a 1" or larger hole between that and the pipe.


So..... Anyone know reasonable prices for a new exhaust system? Muffler and cats? Might try to do it myself if I can bolt it together and not have to weld it...

 

Not sure where you are in NY, BFE isn't listed

Searched around on CL for minute in the surrounding areas. Maybe one of these are for a DC/SB:
http://cnj.craigslist.org/pts/4327382657.html
http://philadelphia.craigslist.org/pts/4340034687.html
http://baltimore.craigslist.org/pts/4285622577.html
http://washingtondc.craigslist.org/nva/pts/4312031434.html
http://southjersey.craigslist.org/pts/4334207391.html
http://burlington.craigslist.org/pts/4340675074.html

 

Thanks! I'm near Binghamton. Had someone messing with me on here a couple years ago, so I changed my location.