P0300 how to fix multiple cylinder misfire and causes

Question

my 1996 mitsubishi galant recently started acting up. i scanned it and it says multiple cylinder misfire. i changed out the plugs and wire, the injectors, and the EGR valve and it still does the same thing. Can someone please assist me in figuring out what to do next. Thanks in advance....

Answer 1

Hi there,

Check for intake gasket leaks. With the engine running, spray some carb cleaner along the intake and see if the engine speed increases. If it does, then you have a vacuum leak. You could also have a timing issue. If the timing belt has jumped a couple of teeth it can give you multiple misfires like this.