Hello,
I just installed a new slightly taller sink and vanity in my bathroom and now the water pressure is lower. I noticed that when I connected the new faucet I had to pull on the pipes a little bit to get them to reach the new faucet.
Could this be the reason for the lower pressure and if so how can I solve this problem?

Thanks!

Pipes do not like to be pulled since there is very little flex. Is it possible that you kinked a supply line? Try opening the stop cocks under the sink and test for pressure there. Get a bucket and a rag, maybe have a friend turn the main on/off for you while you test.

[grinz]
You are braver than me. I think stressing a pipe is a good way to set yourself up for a problem.
Disconnct the pipe going into the faucet, see if it has good flow going into a bucket.