Ok, I have done a lot of searching on here for the converter. But what really happens and should I be concerned about the "real" problem. From what I can tell the 420 is specific to the converter. Is it that the engine is not functioning propery and therefore throwing the 420 code or is it that the converter is bad. I have 91,000 miles on the car. Replacing the converter seems like the most popular answer, but is there really an inefficiency in the burning of the fuel?

 

I don't mind changing or getting parts changed if that is really all that needs to happen, but is that the only reason it would produce the 420 code?

 

Same logic with the 325, I changed the knock sensor about a year ago, so is my car just really hard on knock sensors or is there a problem with a knock in the engine?

Ok, I have done a lot of searching on here for the converter. But what really happens and should I be concerned about the "real" problem. From what I can tell the 420 is specific to the converter. Is it that the engine is not functioning propery and therefore throwing the 420 code or is it that the converter is bad. I have 91,000 miles on the car. Replacing the converter seems like the most popular answer, but is there really an inefficiency in the burning of the fuel?

 

I don't mind changing or getting parts changed if that is really all that needs to happen, but is that the only reason it would produce the 420 code?

 

Same logic with the 325, I changed the knock sensor about a year ago, so is my car just really hard on knock sensors or is there a problem with a knock in the engine?

 

Cat efficiency codes are frequently due to lazy/bad O2 sensors. Either have a shop test the sensors (front one very likely bad - expecially if its the original at that mileage) or cross your fingers and throw one on yourself.

 

Carl

Cat efficiency codes are frequently due to lazy/bad O2 sensors. Either have a shop test the sensors (front one very likely bad - expecially if its the original at that mileage) or cross your fingers and throw one on yourself.

 

Carl

 

what he said.

The front o2 sensor has to be OE, the rear can be generic.

 

nipper

Cat efficiency codes are frequently due to lazy/bad O2 sensors. Either have a shop test the sensors (front one very likely bad - expecially if its the original at that mileage) or cross your fingers and throw one on yourself.

Yes, front/rear/both oxygen sensors can cause real or seeming problems with the catalytic converter. In general, the front O2 sensor output is used in conjunction with the ECU to determine/set the fuel/air mixture, while the rear one's output is compared with the front's to get the cat efficiency. Here's something to read that might prove interesting:

http://www.troublecodes.net/articles/catfailure/

I had that code on my 99 Forester last year. I changed the front ox sensor and away it went.

Ok, I have done a lot of searching on here for the converter. But what really happens and should I be concerned about the "real" problem. From what I can tell the 420 is specific to the converter. Is it that the engine is not functioning propery and therefore throwing the 420 code or is it that the converter is bad. I have 91,000 miles on the car. Replacing the converter seems like the most popular answer, but is there really an inefficiency in the burning of the fuel?

 

I don't mind changing or getting parts changed if that is really all that needs to happen, but is that the only reason it would produce the 420 code?

 

Same logic with the 325, I changed the knock sensor about a year ago, so is my car just really hard on knock sensors or is there a problem with a knock in the engine?

Hey,

My forester has never had this issue, however I recently asked my Mechanic about it,moreover he stated that car manufactures have to warranty the Coverter (mine has two) for 100,000K.

Good Luck with it.

John

http://www.ultimatesubaru.org/forum/showthread.php?t=52917&highlight=0420

 

please read this, all the way to bottom, you may be coverd by a recall that is casuing your problem.

http://www.ultimatesubaru.org/forum/showthread.php?t=52917&highlight=0420

 

please read this, all the way to bottom, you may be coverd by a recall that is casuing your problem.

 

EXCELLENT!

 

Carl

Thanks for all the information guys! I will replace the front O2 sensor, probably needs it anyway, and we'll see what happens. Can I just call Subaru to find out if the car has been in for the WXW80 recall? I bought the car used 2 years ago with 70,000 miles.

[...]Can I just call Subaru to find out if the car has been in for the WXW80 recall? I bought the car used 2 years ago with 70,000 miles.

Used or original owner, if properly done, it should be on record. In theory, the VIN is all that's needed to check.

As for the WXW80 recall, I assuming this was just for certain 00 models. I haven't gotten a notice for my 00 OBW although my car has the same problem with prematurely wearing out O2 sensors. It happened around 80,000 and 115,000 w/ the CEL. I have had 3 recalls performed on my car but none were in regards to this campaign. Any one else have any thoughts?

http://www.ultimatesubaru.org/forum/showthread.php?t=52917&highlight=0420

 

please read this, all the way to bottom, you may be coverd by a recall that is casuing your problem.

 

Sorry, but I originally posted this question incorrectly under the original thread, but here is my question again....

 

Does anybody know if Subaru is still honoring recall WXW80? I have a 2000 OBW w/ 170K miles with the same problem. I have never replaced the sensors because the car runs fine and I seem to get decent mileage. (24MPG avg.) This recall did not come up for my VIN. However, I read on some other thread that Subaru covered it for other VIN's not included in the original recall. Does anyone know and should I take it to Subaru or would I be wasting my time...

 

Thanks as always for sound advice!

For what it's worth (if you aren't covered by a recall), Code 420 went away for me when I changed the spark plugs, despite the fact a mechanic told me the inside of the front converter was broken apart. Car ran a lot better after that too.

For what it's worth (if you aren't covered by a recall), Code 420 went away for me when I changed the spark plugs, despite the fact a mechanic told me the inside of the front converter was broken apart. Car ran a lot better after that too.

 

I thought about that as well, I wonder if that would help with the 325 knock sensor also, a while ago I got a CEL and the car was running real rough, checked the wire and it was pretty much off the spark plug, re-attached all and everything was fine. I should probably replace the wires as well, general maintenance I guess!