If you want to trip to Khon Kaen from Pattaya by bus, you can use bus operators which have route to Khon Kaen from Pattaya are as folloiwngs;
407 Pattana : The bus terminal is located in Gas stand at Sukhumvit Road, close to three way intersection of Sukhumvit Road and Pattaya Klang (Central) Road.
>> Go to 407 Pattana
Chan Tour :The bus terminal is located near three way intersection of Sukhumvit Road and Pattaya Klang (Central) Road.
>> Go to Chan Tour