I've got a 2016 Toyota Camry that's been running like a dream for years, but over the past month or so I've noticed a rough idle that's been getting progressively worse – the engine feels like it's stumbling slightly when I'm stopped at traffic lights, and my fuel economy has dropped noticeably. I've already changed the spark plugs and air filter, and I've tried running a bottle of fuel system cleaner through the tank, but neither has made much difference, so I'm starting to think it might be a fuel injector issue. I'm not sure if they're clogged or maybe just dirty, but I've read that injector cleaning can sometimes restore smooth idle and improve fuel efficiency if caught early. I'm based in the MBZ City area and I'm looking for a workshop that actually has the proper equipment to do a professional injector cleaning rather than just pouring some additive into the tank and calling it a day. I've heard there's a premium fuel injector cleaning service in MBZ City that uses ultrasonic cleaning and flow testing, which sounds like the right way to do it, but I'd rather get a solid recommendation from someone who's actually used a particular shop before I hand over my car. Has anyone here had their injectors professionally cleaned on a similar Japanese car and found a noticeable improvement in performance? Also, roughly how much should I expect to pay for something like this? Any advice would be really helpful because I'm getting tired of the rough idle and I want to get it sorted before it leads to bigger problems. Cheers.