2002 Outback P0420 - 2002 Subaru Outback

On this website you find fuse box diagram and description for Subaru Outback (2001 - 2002)

SubaruOutback 2001 2002 fuse box diagram Auto Genius

P0420 SUBARU - Catalyst System Efficiency Below Thresholdhttp://engine-codes.com/p0420_subaru.htmlForum CodePossible causes- Three way catalyst converter Bank 1
- Exhaust tube
- Intake air leaks
- Fuel injectors may be faulty
- Fuel injector leaks
- Spark plugs may be faulty
- Improper ignition timing
- Engine Control Module (ECM) Tech notes The most common cause is the three way catalytic converter Bank 1 is worn out. Changing just the catalyst O2 sensor usually does not repair the problem. If the P0420 code is combined with other codes, try fixing the other codes first.

P0420 Usually indicates a bad catalytic converter or a bad oxygen sensor. Since you car is 2008 my money is on the oxygen sensor. Or it could be something as simple as an exhaust leak. The cruise control will keep flashing until you get the CEL fixed

P0420....Catalyst System Efficiency Below Threshold (Bank 1)

I have a 2002 Nissan Altima. Can anyone tell me what these codes are? And how to fix them? P0420

I do not know for sure if this is the problem you are having, But, I have noticed that from 95 up to 2002 I have seen a lot of PO420 codes that have been just the sensor. I do not know if it was a weak sensor or just that program telling it that it is below threshold. I did notice that if the vehicles are run for a long trip at highway speed it goes out. I wish you luck and have a great day.

that code is saying you have a problem with that system. if you go to autozone thay can print that code out for that tells you what to check. other then that you may need to get it diagnosed by a professional

CODE PO420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK I * CODE PO325 KNOCK SENSOR NO.1 CIRCUIT MALFUNCTION BANK NO.1 OR SINGLE SENSOR

A p0420 code is set when the computer determines that the catalytic converter isn't doing it's job. In almost all instances that code can't set as a result of a bad o2 sensor so they probably didn't have to be replaced. The catalytic converter will need to be replaced, prefferably by an oem part. This can be pretty expensive and should be considered before purchasing the vehicle.

I have replaced a few bad converters on late model subarus in the past few years.

PO420 is for catalyst system efficiency below threshold. I have seen this many times on vehicles from 96 up. It is due to the system not burning the fuel at what it considers an acceptable rate. Todays fuels are not the best we could have for internal combustion and sometimes it will set off the light. I tell my wife she is too easy on the car and it's not burning the fuel proper. After a couple days it goes out. It will not harm your engine and should go out again. Fuel system cleaning additive will also turn of light. Good luck and enjoy your Subbie. Greatest car ever Built.