http://www.lostmycat.com/lostcat.html

Have you tried sprinkling used litter around your garden...yucky I know, but your cat will recognise the smell if he walks by.

As previously mentioned he is likely to be hiding during the day and might move at dusk or dawn. So these are the best tme to search and call for him.

As he is an inside only cat, he is statistically likely to be very close to your home but hiding. If he is scared he might ignore your calls, until you actually find him.

Look under every bush, hedge, flower pot, rattling food tin might help too. Get all neighbours to search their gardens, sheds ad garages.

Is he particularly close to one of the other cats ? If so stick that cat in a carry case on your porch preferally meowing, this might prompt interest from Pete , if he is hiding close by.

Above all don't lose hope, being outside is not a death sentence. Cats are naturally attune to nature, even inside only cats quickly adapt to being outside.

Fingers crossed that Pete comes home very soon.