Welcome to RadioReference.com!!! The Sacramento trunked system is a large system and there are a lot of users. You will be much better off with a trunk tracking scanner, especially if all you want to hear is Elk Grove. Certainly you can pick up "pieces" of conversations with a conventional scanner like you have, but it's awful by comparison.
Fortunately right now you do not have to spend much to get a reasonable trunk tracking scanner that will work for this area. We don't have much digital (certainly not Elk Grove) and rebanding appears to be a couple of years away as well.
If you are buying a new scanner, I'd suggest the PSR-300. I bought mine from ScannerMaster (see link at top of page) for $149. Over the past year I have sold several PRO-95s and PRO-97s for less than $100 each. Ironically people seem to be getting nearly the same amount for non trunk trackers.
I mostly listen to the Sacramento trunked system with PRO-95s. Another feature I highly recommend (all my scanners have this) is "alpha tagging". The channels display with a text description rather than just a code or frequency.