Expert: Sean Halliday - 10/21/2006

Question
I have a 1994 infinity q45. One day while driving home from work, the engine light came on I stopped at the red light. The car was kind of vibrating, then after a while the engine light turned off.  Does this have something to do with the spark plugs?  How often do you change them?

Answer
Possibly yes it may be the plugs but it depends on your regular maintenance.If the light came on get it scanned for why it came on.(The computor stores the fault code).Theres a lot of reasons why the car would vibrate as its more than likely it had a misfire.Plug change is usually 50000 miles depends if you use platinum or regular plugs but most modern cars are platinum.Regular plugs are changed  about every 10000 miles.