Hi everyone! New guy here with a 01 5.3 1500 Silverado. I'm having issues with my truck eating gas like it's a 5.9 dodge gas motor. It isn't throwing any codes but I was told running a quick scan of the sensors would tell me alot. Of course I have no clue what I'm looking at so I'm hoping you all could tell me something.

 

Per the screen shots nothing jumps out, long term fuel trims are close to zero like they should be. But the Bank 2 sensor 2 mv does not match the bank 1, they should both be around same range if the cat converters are doing their job correctly. If in the live data stream the rear o2 sensor is bouncing around like the front, that likely means a cat converter is bad.

Have you do any tune up related things yet?

Like spark plugs, air filter, cleaned the MAF sensor, fuel injector cleaner. Front o2 sensors are on avg only good for 100k or less before they can start being slow and effect fuel mileage.

You could check the condition of the diffs, metal filled fluid could mean extra drag and a soon to be problem. Big wheels and tires can reduce mpg and not have the correct PSI can do that too.