I just pulled these codes from my blazer this afternoon where do I start? I just bought this car and it’s got a small electrical leach so it has a negative terminal switch that I can disconnect, aswell I found and replaced some dry rotted vacuum lines by the brake booster running to the intake manifold please lmk where I should start
P0106

P0112

P0113

P0117

P0118

P0121

P0131

P0132

P0133

P0134

P0135

P0143

P0144

P0146

P0147

P0151

P0152

P0153

P0154

P0155

P0171

P0172

P0174

P0175

P0300

P0325

P0327

P0401

P0404

P0420

P0440

P0442

P0446

P0461

P0500

P0601

P0603

P0604

P0605

P0704

P1133

P1134

P1153

P1154

P1441

U1026

U1042

U1192

U1193

C0265

C0237

C0226

 

Without knowing the history . And Since you have a list of the codes, with that extensive list I would start with clearing them and do a full test drive cycle and see which ,if any, come back. Without disconnecting battery first . That will give a possible starting point .
With that many and variety of codes possibilities could include : loose/ bad wiring at PCM , bad ground connection somewhere , simply related to ground disconect switch , to failing (unlikely if runs semi ok ) PCM . But clearing and see which come back could help narrow down actual possibilities
Also note any performances issues you seem to notice ?
Then work on parasitic drain on battery issue