Nexus 4 auto dialing extension does not work I used to own a T-Mobile Mytouch 4g before, which had the pause character before extension otherwise 'p' on that handset and it was working fine.

Now, I own and use a Nexus 4 and I understood that the pause character on the Nexus 4 is ',' (a comma). 

I replaced all the contact entries that had a 'p' with ',' (a comma) in my contacts. And now it is not working, basically, what happens is when I make the call using that contact's number, the number gets called but the extension is not dialled automatically.

Anyone would know how to fix my issue?
I had the same problem. I changed in the google voice settings to only use it for international calls, which fixed the problem. 
When dialing out using Google Voice, I can't get the auto extension feature to work, unfortunately