Skip the auto shop - Our mechanics make house calls

Q: P0300 code random misfire code

asked by on

My 1999 GMC Yukon slt has been having this P0300 random misfire code come on but it come on and go off every week and when it does its hard to start my truck I have to hit the gas to get it started

Hi. Several components could cause this problem - old, failing plug wires, old plugs with wide gaps, worn or corroded distributor cap or rotor contacts, failing distributor pickup coil issues, or failing ignition coil packs. Diagnosis with proper electrical testing gear is the only way to isolate random misfire issues. For further help, a certified professional from YourMechanic, can come to your car’s location to inspect the misfiring issue and move forward with repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. P0300 code random misfire code

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Battery dies when car parked

Hi there. Your vehicle battery becomes weak, may just be a bad battery. The hard starting, may just be slow cranking RPM. Being able to drive a few miles and the battery will hold a few hours, leads me to...

Q: RPM drops while driving

Hi. The next step to take is check the engine for vacuum leaks and check for any loose or broken hoes. I would also check the pcv valve and check the level of the transmission fluid. The transmission could also...

Q: Replaced my battery and replaced ends to the battery cables - does not want to start until I turn it over a few times - I think it my main cable.

Billing question sent to CS for the cost of replacing the positive (+) battery cable to a 1999 Dodge Ram 1500, along with the customer wanting to know where to go to install new seat belts.

Related articles

P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.