2001 Cadillac deville p0300 code

Question

It rained hard for two days did not drive car.. After rain started car immediately got p0300 code.  Car runs great first thing in morning. Then when warms up. It throws code and runs very bad

Answer 1

Hi there,

This is usually a result of bad ignition coils. It takes certain circumstances sometimes for the coils to act up. Try spraying some water on the ignition coils with the engine running to determine which coils are misfiring. Sometimes when you run this test you will see arcing. If not, replace all the coils.