jman11 Posted January 11, 2006 Share Posted January 11, 2006 I know there are a lot of threads about the catalytic convertor 420 code. I had a quick look through a few of the old ones and I haven't been able to find anything about the code magically fixing itself. Here's the story: 2000 2.5RS with 122k miles. Last winter the code for the 420 catalytic convertor came up. I cleared it, erased it and ignored it. It came back on. I'm a grad student, the part costs about $500, so I continued to ignore it. Well it goes off after a while (I think it's 40 warmup cycles without an error) and it doesn't come back. I make sure there are no codes and I take it in to have it inspected and emissions tested and it is all OK. So I haven't worried about it since, and of course it came back on a couple of days ago. I'm probably not going to fix it any time soon, I'm just curious if anyone has any ideas why it appears now? I'm also putting this here if anyone else gets this light (from looking at the board they seem to pop up about now) they can try to ignore it and hope it disappears over summer. I've got a couple of theories, that might work First, the cold weather, something might mess it up. Second, the winter additives they put in fuel (I'm in PA, so it's cold here). Third, carrying me after Christmas when I'm a little fatter. Fourth, I might just be a lucky bastard. Link to comment Share on other sites More sharing options...
cookie Posted January 11, 2006 Share Posted January 11, 2006 My Forester has about the same mileage. I figure the cats are borderline now and I knew oxegen sensors should be cahnged around 100,000 miles. I changed the front ox sensor and the light has stayed out for about a month. My light only came on when someting cooled the cats enough to throw off the efficiency.The real cure will probaly be to change at least the front cat, but if the light stays off for a few more months it might mean the oxegen sensor was enough to get by for a while. I am sure I don't have to tell you how much cheaper an oxegen sensor is that a cat. Link to comment Share on other sites More sharing options...
rugbyben Posted January 13, 2006 Share Posted January 13, 2006 The similarities are killing me. I am also in central PA, (State College) I have a 2000 (its a 2.2L though) and i kept getting the P0420 code... Just curious where do you get your gas? im wondering if maybe a suplier here is suspect. Anyway see my thread about the PO420 code for what i had done. i dont know if it worked yet though. Link to comment Share on other sites More sharing options...
jman11 Posted January 13, 2006 Author Share Posted January 13, 2006 So, we apparently live in exactly the same town. I'm also in SC, a grad student in maths at PSU. You play rugby? My old roommate, Sam, played last year. My cars a silver 2 door coupe if you've seen it around. My gas usually comes from the Sheetz up near Walmart, the Unimart on Atherton where it meets Pugh or a Turkey Hill down in Carlisle. The only thing is I tend to get it from the same places all year. Whereas the code is only winter. If I had a scantool I could clear it more reguarly and test it. As it is the nearest place to get it done for free is at the Autozone in huntington. Link to comment Share on other sites More sharing options...
Bmm001 Posted January 13, 2006 Share Posted January 13, 2006 My mechanic told me it could be as simple as snow or water getting splashed up on the cat and preventing it from heating up properly. However, he said if the code continues to appear, coupled with a noticeable loss of power (especially going uphill), the cats are clogged and must be replaced. Often, he says, the innards break down due to rough roads (all the shaking and clunking around) and bingo, the cats are clogged! Just thought I'd throw in my 2 cents since I too have experienced the 420 code. Brian M. Link to comment Share on other sites More sharing options...
rugbyben Posted January 17, 2006 Share Posted January 17, 2006 Cool. You can actually use the code tool they have at the Auto Zone on North Atherton St. Near CVS and Wendy's. Thats where I go. I see a lot of Subys here. is yours the silver WRX with the nice Cat-Back system? Every time i see that it sounds really great. nice low tone not like all those imprt tuners who cars sound like weed wackers. I drive the green imprezza outback. Mine is one of two in town that has the hood scoop and spoilers. See you around. P.S. I am getting my cats replaced today under the warranty because of the Po420 code. Link to comment Share on other sites More sharing options...
jman11 Posted January 18, 2006 Author Share Posted January 18, 2006 Mine's just a 2.5RS coupe. Back from when they still existed, and before the WRX. It's the old body style, with the flat headlights. I don't think there are any other silver 2 doors in town. I'm not sure I've even seen one other coupe of any colour. The code disappeared, so whatever caused this Catalytic converter light must have been a once off. I'm thinking the CC must be close and it's just random stuff (like water bouncing up to it) that must be giving it grief. Link to comment Share on other sites More sharing options...
rugbyben Posted January 19, 2006 Share Posted January 19, 2006 Cool. The guy im talking about it is a WRX newer body style. I also saw an STI yesterday, blue (because 99% of them are) but this guy put the old school double racing stripes over the top. Well best of luck. maybe I'll see you around some time. Link to comment Share on other sites More sharing options...
2X2KOB Posted January 19, 2006 Share Posted January 19, 2006 The P0420 code is very common on these, and it's not always the cat. Mine was fixed by replacing the rear oxygen sensor - I used a generic replacement from oxygensensors.com. For off-road use, there's also this: http://www.scoobytuner.com/products/?productID=191 There is a belief that the ECU is too sensitive on setting this code. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now