My 1999 Honda Accord Ex - Check Engine Light - P0420?

Question

My Accord got a check engine light - P0420. the car drives fine. i went to auto zone and they said it might be a problem with catalytic converter. how much is the actual cost of replacing?

Answer 1

The cat alone cost around $600,so total around $700.That is Honda part,aftermarket part will last a couple months then light on again.

Answer 2

Check engine light could be from the EGR valve, oxygen sensor or anything. Unhook your battery, leave unhooked for 2minutes, rehook and see if light goes off, if you don't have airbags, refer to owners manual about that. Then follow directions about unhooking battery if you have airbags. Be VERY CAREFUL. Chances are if it does go off and then later come back on, its probably your oxygen sensor or EGR valve. God Bless and good luck. Todays cars, the light will come on if you sneeze because they are so sensitive.

Answer 3

What has happened is that the ability of the catalytic converter to process the exhaust gasses and convert the harmful CO, HC and NoX to harmless CO2 and water has diminished over time to a point where the capacity of the catalytic converter to do the conversions is less than 50% of its original capacity.

The converter uses up a microscopic amount of the reactive metals in the chemical conversion of harmful exhaust emissions to harmless emissions each time the vehicle is used. over time the amount of the material that causes the chemical conversion diminishes. Because of the federal emissions laws, when the on-board diagnostic system judges the capcity to be less than 50% of the original capacity then the failure code P0420 is set and the check engine light is turned on.

the car will not stop on you nor break down. the check engine light simply means that the catalytic converter should be replaced to restore the car to compliance with emissions regulations.

as for your options, if your State does emissions testing (smog checks) the car won't pass the test with the check engine light on. In that case, technically you can drive the car until you need that emissions test to register your car. One downside of doing so is that if thre were another problem with the engine control system you wouldn't know it because the check engine light that would alert you to that subsequent problem will be masked by the light on your dash that you assume is for the catalytic converter.

I don't know what the availability of aftermarket replacement converters is in your area. In California there are no aftermarket converters that are BAR certified for use as replacements for OBD-II cars (none certified for Hondas after 1995),  The Honda replacement converter will run you between $1000 and $1200 for parts and labor.  If your not in California you may be able to find an aftermarket converter.   If you can find an aftermarket converter in your area go for it; it will save you at least $500 over the factory price.

hope that helps

Answer 4

Check this site.  http://www.obd-codes.com/p0420

If you end up changing the O2 sensors, make sure you use the ones specifially made for the car if you have a ULEV engine.  Its written on the top of the engine.  Generic sensors do not work.  Before you do change any sensors try the no cost options in the web site.