Low Idle and running lean

[Doubeleive]

There was at one point same codes too which is weird

The same code can come up as "history" meaning at some point the code was active and then it passed ok, then became active again.

 

[justirv]

Okay so I am sorry about the delay in reply I had to do a bit of work irl (unrelated)
My Truck is a 2004 Chevy Tahoe LT 5.3 V8 w/E85 FF Tech it is the 1500 series it has 256,904 miles on it and current codes are P0300 Random Misfire Detected
And P0171 System to Lean <---This one throws 2 times and it says most likely solution is to clean the fuel injectors. So I just put Lucas injector cleaner in on a half tank and the AZ tech said to run it till empty and gas up on E91 and use a second one to finish it off with the cleaning.

My 2002 Tahoe Z71 5.3 had this problem, which got worse with cold weather. I too did the O2's, MAF, etc., before I replaced the intake manifold gaskets... in this instance it cured the problem.