AJJAZUO
If it’s just 2 missions that are missing OP, then you should only need to do those 2 again for the achievement to pop 
Ya, just do those 2 missions again!
ZAKD
Can someone please help me how do you unlock the rest of the campaign maps on halo 3 odst?
> 2533274813317074;2:
> If it’s just 2 missions that are missing OP, then you should only need to do those 2 again for the achievement to pop
That should do the trick!
> 2533274949937738;5:
> Can someone please help me how do you unlock the rest of the campaign maps on halo 3 odst?
What do you mean unlock the rest of the maps in ODST? All the campaign maps should be unlocked. If you’re playing on the original ODST, the only way those maps would be locked is if you’ve never played through campaign before. On MCC, they’re all unlocked already
Okay here’s what I’m really trying to do: unlock the last 2 armor attachments for the cqb helmet in reach. Now I just beat the mcc halo 3 odst campaign on heroic but it’s not transferring. Data hive and coastal highway are showing up as locked maps on my original odst campaign disc. Now I’m trying to see if doing any of the achievements in odst will unlock the rest of the maps because everything including taryazi plaza or whatever is beaten on legendary. Does this make any sense?
> 2533274949937738;7:
> Okay here’s what I’m really trying to do: unlock the last 2 armor attachments for the cqb helmet in reach. Now I just beat the mcc halo 3 odst campaign on heroic but it’s not transferring. Data hive and coastal highway are showing up as locked maps on my original odst campaign disc. Now I’m trying to see if doing any of the achievements in odst will unlock the rest of the maps because everything including taryazi plaza or whatever is beaten on legendary. Does this make any sense?
You can’t transfer progress between MCC ODST and 360 ODST. Also, not sure what ODST has to do with unlocking armor in Reach.
> 2533274824050480;8:
> > 2533274949937738;7:
> > Okay here’s what I’m really trying to do: unlock the last 2 armor attachments for the cqb helmet in reach. Now I just beat the mcc halo 3 odst campaign on heroic but it’s not transferring. Data hive and coastal highway are showing up as locked maps on my original odst campaign disc. Now I’m trying to see if doing any of the achievements in odst will unlock the rest of the maps because everything including taryazi plaza or whatever is beaten on legendary. Does this make any sense?
>
> You can’t transfer progress between MCC ODST and 360 ODST. Also, not sure what ODST has to do with unlocking armor in Reach.
Maybe he’s miss remembering? I know that completing the Vidmaster Achievements earned you Recon Armor in Halo 3. I don’t think there were any ODST achievements linked to armor unlocks in Halo Reach