jada32819 Posted February 22, 2014 Share Posted February 22, 2014 I have a 1996 Outback with 2.5 engine , has P0420 code, any suggestion , there are no any other code for engine misfire Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted February 24, 2014 Share Posted February 24, 2014 Welcome to the USMB. I'm going to move your thread to the new gen forum. Quote Link to comment Share on other sites More sharing options...
Suzam Posted February 24, 2014 Share Posted February 24, 2014 How may miles on the car? A p0420 can be the result of a o2 sensor getting lazy. If it's running fine you can reset it if the CEL is still on and see if it returns. I had one that would pop the CEL after a highway run at higher speeds every 6 months or so. I'd just reset it since it ran fine and there was no drop in MPG. As long as it was well before the emission check the car still passed without trouble. Quote Link to comment Share on other sites More sharing options...
luko Posted February 24, 2014 Share Posted February 24, 2014 What is the vehicle's history? such as any new parts on it? Quote Link to comment Share on other sites More sharing options...
Sdam87 Posted March 2, 2014 Share Posted March 2, 2014 (edited) Probably a poop'd out o2 sensor, or you need a cat.. If I remember right, the 420 codes are cat related. And or stoner related.. heyoh! haha Edited March 2, 2014 by Sdam87 Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted March 2, 2014 Share Posted March 2, 2014 there are many things that can cause that code. even exhaust leaks. http://www.subaruoutback.org/forums/66-problems-maintenance/49537-p0420-diagnosis.html Quote Link to comment Share on other sites More sharing options...
luko Posted March 2, 2014 Share Posted March 2, 2014 Catalyst efficient code...Remember catalytic converters just don't go bad...something causes them to go bad, so if you just slap a new set of cats on it chances are you'll have the same problem down the road Quote Link to comment Share on other sites More sharing options...
idosubaru Posted March 3, 2014 Share Posted March 3, 2014 how long have you owned it? when were the headgaskets replaced? annoying code. there's about 1,000 things that can cause it. best off just ignoring it. being a 1996 you can get an exemption from emissions due to a 1996 specific issue. so it shouldn't matter at all if the check engine light is on. fix any exhaust leak seafoam the intake fuel additive new NGK OEM plugs New OEM wires you're not likely to find a mechanic capable of properly diagnosing what is causing it so they'll usually just throw a new catalytic converter and O2 sensor at it even though that's not likely the cause. 1 Quote Link to comment Share on other sites More sharing options...
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