At 2 years old he may have not been completely ready to potty train and that may be why he has regressed to peeing his pants again.
I don't normally recommend going back to diapers but in this case since he's only 2 I'd put him back in diapers and forgot about potty training for awhile.
I'd rather change a wet diaper instead of wet pants all the time. And it's more sanitary for him to pee in the diaper then on his clothes.
Or at least use pull ups training pants to catch the urine. But training pants usually cost more that regular disposable baby diapers and the regular disposable diapers will absorb better and be less likely to leak.