Nearly scammed me out of $1100 dollars. My car was stalling randomly. They tried to tell me all 4 cylinders were misfiring. (Despite no check engine light) They told me I needed to replace all spark plugs and coils, AND do a valve adjustment. (About $1100) A simple test from another mechanic found that it was a bad EGR valve; a $400 fix. The car has been running smoothly since for almost 2 years now. Colonial Honda would have run my bank account dry, and still not have fixed the problem!