My 2008 Hyundai Accent is running rough and using more fuel, will hardly run a speed of 40mph. I already replaced two coil packs and checked the other two along with replacing the spark plugs. My OBD2 meter indicates a Catalyst System Below Efficiency P0420 code. The care has a front and back O2 sensor.. needs some help on the next step
Don't throw a bunch of parts at it get a can of mass air flow sensor cleaner and clean the three prongs in the middle the mass airflow sensor regulates the air the gas from the gas tank is read by the computer and that equals how much gas and how much air the vehicle needs so clean the sensor I think your run well
Co0de p 0420 refers to vat converter bank 1 below threshold ===causes ---cat converter---wiring ---HO2S ( heated oxygen sensor in the exhaust manifold bank 1 before the cat converter) you have possible 2 problems
1--- the HO2S is faulty but that alone will not result in what you describe
It's function is to read the exhaust gas composition out of the combustion chamber and report to the ECM so that the air fuel ratio can be maintained according to set parameters
the most likely problem is a failed cat converter that is blocking the exhaust system
with the exhaust not flowing freely, there is excessive back pressure and that stops the exhaust gas from exiting the combustion chambers and so rpm is restricted and the economy takes a nose dive
I would consider that you have the cat tested and /or replaced as that will be the base fault causing the problems
SOURCE: 2000 Hyundai Accent will suddenly stall and wont restart
Have someone check the idle sensor. I had to have mine replaced along with another that I don't remember which one is was.
SOURCE: stopped while running
I had the same problem. I found out that the fuel pump was not putting out enough pressure. changed the pump and bam down the road I went.
246 views
Usually answered in minutes!
×