Cat c15 loss of power

I’m driving home now So have one there. the elbow was still on but the clamp was completely loose

 

No blow bye

 

Loss of power shake and stutter. Idles fine so I called wrecker get it to cat all tests good inj cutout, solenoid. And fuel restriction. I keep hammering it and it seems fine just don’t want to put 80k on and be dead again.

 

I can hear something clunking around.

 

Yes

 

Under load

 

The motor. I’m not sure where exactly more to follow up in the next few days. Can’t tell if clunking or fuel knock. I have a mechanic that’s worked a Freightliner for 15 years on it. He’s confident.