Greetings,
I have a 2001 Xtreme blazer. 2wd, stock motor and transmission.
I’m having an issue with power loss. Whenever I’m pulling my utility trailer (5x10) I noticed it’s difficult for my blazer to pull up hill. It losses power and the check engine light starts to blink rather than a steady light.
I have replaced the fuel pump, FPR, EGR, full time up with ACDelco parts, fuel filter, ignition module...I’m stumped.
If im not pulling anything it runs just fine, no problems. It’s only when I’m pulling or diving down the interstate while pulling up hill. It’s went so far as to shift into first and just barely was creeping...maybe 5-10mph.

Any help would be appreciated.

Thanks