any body help me out with my monte i got the codes/probs thanks
 

so i got my 9 monte z34 back from my uncles shope today and he gave me a list of the codes that the check engine light was on for, then he wrote stuff next to it telling me what that meant, but i got no idea as of what i gotta buy to get it fixed, cause he told me even if he did the work and gave me a fair price it was around 500-700$ worth, so i fig id do as much of it as i can, so if you can help me out by telling me what parts i gotta get or what it means that would be great thanks, heres the codes and what he has next to them

PO133- O2 signal slow bnk 1 sen1
PO300- random cyl misfire detected---- i think i got that fixed i replaced the coil if thats wrong please let me know thanks
PO410- secondary air inj sys
PO420- cataylt efficiency low bnk 1--- my exhaust is a little leaky right befor my cat so i think afta i get that welded bak that might tak of that wbu??
P1133- HO25 bnk 1 sns 1 insufficiwnt switching got no idea on that 1

so if any body can help me out by telling me what all that means i would love it thanks guys

RE: any body help me out with my monte i got the codes/probs thanks
 

Wayyyy tooo many problems. I hate to tell you but to do this right, someone who knows what they are doing will need to have a tech tool giving live data.

RE: any body help me out with my monte i got the codes/probs thanks
 

i think most of it has to do with the exhaust being leaky, ima fix that up next monday wheni get the day off from work and pull out the welding kit, then i gotta replace the o2 cencers and ma get it rechecked, hopefully dat will change a few things in the comp