It is R134 but have you verified the freon level? There's a sight glass you can check on the evaporator canister. If it's full, then it won't be the freon so don't waste your money on a bottle. Mine's not working either and I need to look into that also but I have too many other higher priority projects right now.:ylsmoke:
To help troubleshoot the problem and also locate important components like the site glass to determine the freon level, check page 55-18 of the factory service manual (FSM). If you don't have the FSM, you can download it for free from mitsubishilinks dot com. Just follow the procedure there.