I fish the los banos area quite regularly and the only canal I fish that turns out decent for me is on cotton gin road. Nothing huge, I've caught up to 3 pounders and that's it, but there a good amount of cats in there. In the evening you have a decent chance of hooking up wioth some stripers too. But I usually fish the lb game refuge, I do great in there, I've caught up to 6 1/2 pounders in there this summer. Really hot spot, but it's only open till september 15th so hurry up. I usually fish where the ruth lakes come together, there's a little dirt bridge and either side has good amounts of large fish. Grab a map on your way in and you'll be able to find it. Liver, anchovies and whole shad have worked the best for me. Good luck, let me know how you do.
Hunter