Q: Was running bad and now warning lights are on

asked by on November 03, 2015

The other day my 2007 Hyundai Santa Fe started to run really rough and I was pretty concerned. Sure enough, the check engine light popped on to tell me that, yes, there was a real problem here, at just 44,000 miles. I think it is just an electrical issue, because sometimes I can get the engine to run alright for a minute by starting the car up. How can I diagnose this problem? Can I do it myself?

This misfiring may occur when spark plug wires are exposed to oil and short out the ignition wire. This is caused a leaking valve cover and a broken seal around the spark plug holes. You will need to have your vehicle computer scanned for misfire codes P0300 through P0306. This will help the mechanic determine which cylinder is misfiring and allow them to check that cylinder by pulling out the plug wire and examining it for oil. If oil is found then it is recommended to replace the valve cover gaskets along with the spark plugs and spark plug wire boots. You can schedule an inspection of your engine problem to have these repairs performed.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I program the HomeLink garage door opener for non-rolling code garage doors?
Garage doors that were made before 1996 are referred to as non-rolling code. Here is how you program them with your HomeLink garage door system. Insert your key into the ignition, and turn the ignition switch to ON/RUN. Locate the...
How do I use the floor mats?
While they might not seem like particularly important accessories, your car’s floor mats actually serve essential purposes. They protect the carpeting from dirt, debris and wear and tear. Properly used, they can help your interior last for a much longer...
Wire came off of starter
Hi, if this is a large diameter wire like a battery cable then it may be the cable to the starter terminal. If it is a smaller wire, it may be a memory wire for the engine controls and things...
Check engine and cruise control lights come on simultaneously
Hello. When the Check Engine Light comes on, it disables the cruise control (https://www.yourmechanic.com/article/how-cruise-control-works). I would need to know the code to be able to tell what may be going on. I typically start by scanning the computer for codes...
How much would it cost to convert a 98' range rover from air suspension to spring suspension?
The suspension would need to be changed over with a kit like at this web site [ http://www.roverparts.com/Parts/9520LB ] The cost for the parts is almost $700 and you are looking at approximately 8 hours labor to install the kit....
Very slow acceleration starting. 1990 Volkswagen Cabriolet
Hello. There could be a problem with the throttle cable that goes from the gas pedal to the throttle body. There could also be a problem with the throttle position sensor (https://www.yourmechanic.com/services/throttle-position-sensor-replacement) in that it may not be reading the...
Won't start - not getting fuel into the injectors
Hey there, thanks for writing in. Lack of fuel pressure here often points out a clogged fuel filter (https://www.yourmechanic.com/services/fuel-filter-replacement). I would have an experienced technician inspect the fuel system and check pressure at the fuel feed line under the hood....
I have a 2009 Chevy aveo. The temperature gauge is under C and the hold button is flashing. I have a/c and heat is working.
Hi there. When the temperature gauge displays below the "C" - this is typically an indication that either the coolant temperature sensor is damaged or the display gauge itself is faulty, has a blown fuse or there is a communication...

Related articles

P0142 OBD-II Trouble Code: O2 Sensor Circuit Malfunction (Bank 1, Sensor 3)
Diagnostic Diagnostic Trouble Code (DTC): P0142 P0142 code definition O2 Sensor Circuit Malfunction (Bank 1, Sensor 3) What the P0142 code means P0142 is the OBD-II generic code indicating the Engine Control Module (ECM) input from the O2 sensor circuit...
P2078 OBD-II Trouble Code: Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High
P2078 P2078 code definition Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High What the P2078 code means This code will set if the Engine Control Module (ECM) (https://www.yourmechanic.com/parts/engine-control-module), or Powertrain Control Module (PCM), detects a problem with the position...
P0991 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch E Circuit Intermittent
P0991 means that the PCM has detected a variation in the transmission fluid pressure due to a faulty pressure sensor, or transmission failure