Hi!
So my check engine light comes on and i get this message reading " try to slow down or shift up" on my dashboard. Idling while driving and really idling when at a stop. Going uphill it gets lretty damn rough as well. So i got a code reading ( p0300 , 0203, p0303) changed the coil pack on cylinder 3, still not driving right,, spark plugs look fine. What the hell is gong on?????? Please help!!!!!!!!

 

0300 is a generic misfire, 0203 says your #3 injector is malfunctioning, 0303 says you have a misfire on #3. Time to pop out injector #3 and test it out... Recall that misfires can be caused by fuel or spark - so this looks like a fuel delivery issue.

 

Like a fuel injector?

 

yes. the fuel injector. You should be able to find a local shop that will test/clean or buy a replacement. It does have a solenoid switch so it can either fail by clogging with debris or the solenoid can fail and won't pulse properly.