Judging just by HPS is not a reliable way to conclude anything but,
- 170k HPS is low (even 270k) , especially since in pugs dps ignore tactics and take more damage than they should ( cause "its heroic, I won't die" kind of thoughts ). You should definitely look into class forums / paladin discord to get some help to improve yourself.
- 170k HPS even if it is low but the raid is not dying or struggling to survive is still doable.
- Compare yourself to the other healers as well, if they are doing 500+ HPS and you are stuck at 200-300k you are doing something wrong ( similar ilvl ). Knowing how to maximise the efficiency of yours class is part of your skillset
- Paladins are only good healing in clustered up groups aoe , as far as I know, try to hug melee dps and heal those along with the tanks for better performance.
Being removed from a pug group, could be your fault, your raid leader's inability to understand who causes the issue or any number of random other reasons.
The best thing you can do is to look how to improve yourself, so at least some of the reasons to get removed from a pug will be no more.