Lacking power under load

[TreveRs82]

I’m new here, a beginning diy mechanic and on vacation at the moment at the in-laws, so I have some resources but not on my own turf. On the drive down here I noticed my rig (2014 Suburban LS with a 5.3L V8) started lacking power going over some large hills on the highway. I had the pedal floored but could only go around 50 mph (speed limit was 65). I bought the SUV a few months ago and haven’t really had any issues with it. Any ideas what my issue may be?

[diyer2]

Have you given this thing a thorough going over?

Could be lots of things.

[TreveRs82]

My brother-in-law said he knows a guy that knows a guy that would be willing to look at it. I guess I’ll wait to see what he says. 

[TreveRs82]

Ok. So it turns out I needed a new fuel pump because the pressure output was 15-20 pounds below normal and my bank 1 catalytic converter was bad. All is now fixed and running great. 

[diyer2]

Great and thanks for letting us know what fixed it.