Question about 2007 Hyundai Sonata Limited Sedan
Check engine light code po7o8
Posted by Anonymous on
The transmission range switch that detects the shift lever position (N or P) could be short circuited. Replace the switch or correct the wirings.
Posted on Apr 25, 2013
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
I had same problem and my repair shop just replaced a sensor in the tranny. Said it was a defect by Hyundai,but they won't recall it.
Posted on Oct 21, 2008
SOURCE: engine code p0421
Catalyst System Efficiency Below Threshold (Bank 1)
The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.
A code P0420 may mean that one or more of the following has happened:
* Leaded fuel was used where unleaded was called for
* An oxygen sensor is not reading (functioning) properly
* The engine coolant temperature sensor is not working properly
* Damaged or leaking exhaust manifold
/ catalytic converter / exhaust pipe
* Retarded spark timing
* The oxygen sensors in front and behind the converter are reporting too similar of readings
To Do list
* Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required.
* Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady).
* Inspect the downstream heated oxygen sensor (HO2), replace if necessary
* Replace the catalytic converter
Posted on Jan 19, 2009
Sometimes the mass air flow sensor will become clogged with some miniscule particles of dust or whatever else. When you open up your hood somewhere near where the air filter box is, there will be a hose running from that to the engine, the mass air flow sensor should be somewhere in near there. They are easy to remove and should be held in place with a few screws. Make sure not to touch any of the electrical connectors on the inside or allow them to get dirty. I used mass air flow sensor cleaner from the local parts place but it is a bit pricey. There may be some alternative cleaners available that are not as expensive. Take the sensor to a relatively dust free area and spray it all over with the cleaner and allow to dry. At the same time under the hood where the sensor was spray that area as well. Once the sensor has dried out re-install it and you should notice an improvement. If the problem still persists you may need to change your spark plugs, or spark plug wires.
Posted on Feb 18, 2009
Tips for a great answer:
Jan 16, 2017 | 2003 Hyundai Sonata
Jan 06, 2015 | Cars & Trucks
Mar 23, 2014 | 2001 Hyundai Sonata
Mar 25, 2013 | 2000 Hyundai Sonata
Oct 25, 2012 | Hyundai Motor 2004 Sonata
Sep 13, 2011 | 2001 Hyundai Sonata
Apr 23, 2017 | 2000 Hyundai Sonata
May 30, 2010 | 1997 Hyundai Sonata
Sep 15, 2014 | 2007 Hyundai Sonata Limited Sedan
151 people viewed this question
Usually answered in minutes!