I'm an owner of a 2001 Toyota Echo, 187000 original miles. This tip comes from Scotty Kilmer, 50 yr Mechanic on YouTube, that I'm passing along to everyone. Gumout Multi-System Tuneup Cleaner is awesome for cleaning fuel injectors, fuel system, piston head and exhaust valves. Eats carbon off surfaces to make your engine run smooth. Cost $8 at Home Depot Auto section in store. Pour in gas tank before fill up to mix with gas thoroughly. I swear by this stuff, and has made a wonderful difference in engine performance. Enjoy!