I'm going to throw this out there as a n00b here. I tried the search with little to no avail- I'm semi-'puter illiterate.

 

I have an 02 OBW 2.5 that has received all the usual tuneup parts recently. That includes: O2 sensors,plugs, wires, PCV, SeaFoam upper engine treatment, and 3m throttle plate cleaner. I refuse to believe that the cats are bad at 142k. It just doesn't seem right. Now, I've seen on another board, many people fork out the cash for new cats, and they claim it fixes the problem. I've also noticed that there can be many causes for this code popping up. I suppose I could throw enough money and parts at it to make myself feel better,but I would like to fix the problem correctly.:-\

 

Also, what is the body/ engine designation for this model (i.e.- EJ22, etc)? It is so I can make better use of the information already here.

Edited January 16, 200917 yr by fleming442
update

I'm going to throw this out there as a n00b here. I tried the search with little to no avail- I'm semi-'puter illiterate.

 

I have an 02 OBW 2.5 that has received all the usual tuneup parts recently. That includes: O2 sensors,plugs, wires, PCV, SeaFoam upper engine treatment, and 3m throttle plate cleaner. I refuse to believe that the cats are bad at 142k. It just doesn't seem right. Now, I've seen on another board, many people fork out the cash for new cats, and they claim it fixes the problem. I've also noticed that there can be many causes for this code popping up. I suppose I could throw enough money and parts at it to make myself feel better,but I would like to fix the problem correctly.:-\

 

Also, what is the body/ engine designation for this model (i.e.- EJ22, etc)? It is so I can make better use of the information already here.

 

 

I had the same problem with my 03 H6. My mechanic tells me it's forsure the cat. I have 144K Miles on mine. He's the head tech at a subaru dealer so he knows his stuff. He's going to somehow weld a generic Cat in for me for about 150$ + labour. I Guess he's done it successfully to a few other H6's and everything has worked fine and code gone.

I've posted here that I've had good success with seafoam through a vacuum line.

 

When you say Seafoam upper engine treatment exactly what do you mean?

 

If you haven't run it through a vacuum line I highly suggest it. Just don't do it anywhere the neighbors will think the house is on fire.

 

I usually only do up to '99's so perhaps it doesn't work as well on the later stuff.

What brand O2 sensors are they?

 

Have you checked for exhuast leaks (even tiny ones)?

 

 

nipper

Yes, the SeaFoam was drizzled in the vac. line.

 

nipper, the O2's were Bosch (non-dealer purchase). No, I haven't checked the system for leaks. I'm thinkin' I may just buy the NAPA converter for $350 and get the ebay headers if I do anything with the exhaust.

 

I'm going out to the garage now to put the PCV valve I got from the dealer for $17, clear the code, clean the IAC, and change the oil.

 

I really need to know what the Subaru ECU considers a "drive cycle". I need to take it through MD emission testing, but they won't even look at it if the CEL is on. The last time I took it through, I was being crafty, cleared the code, and drove it in. They told me there wasn't enough data to test. So, I need to get it in there when it has enough data for testing, but hasn't triggered the CEL yet.

You know there comes a time to take it to a shop who can diagnose it better then you can.

 

http://endwrench.com/images/pdfs/OBDInfo.pdf

Personally, I've never had good luck with after market O2 sensors.

 

Have You tried replacing the secondary O2 sensor? It tells the ECU if the cats are operating efficiently.

 

IC that You have changed both sensors.

 

Some guys have had good luck running these, when a free flow, or catless exhaust is installed

 

http://www.energeticforum.com/renewable-energy/1387-o2-sensor-modification-using-spark-plug-non-foulers.html

 

 

 

http://www.scoobymods.com/forums/showthread.php?t=5468

Edited January 3, 200917 yr by zedhead

i beat this drum to death myself. Fron O2 sensor neds to be from a subaru dealer and the rear can be generic.

 

nipper

It's the cats. They go bad. I've been around the block with this issue many times. Aftermarket cats will not solve the problem. They are not efficient enough and you will still get the code eventually. I have had decent luck spacing out the O2 sensor with spark plug anti foulers, I'd say about 80% success rate. It's worth a try for under $10. The real fix is new factory cats and they are big money.

nipper, don't get me wrong. I value your advice as you seem to post good info. I'm guessing you are a dealer tech, no? However, I find it extremely hard to believe that a product that is so near indestructible is going to be so finicky about whether its parts come across the dealer counter, but I have been wrong before. I am also a cheap bastid!

 

I got a code scanner that displays the freeze frame of what caused the code. It said it happened at 2825 rpm with a MAP of 65kps, blah, blah, blah. I found what Subaru calls a drive cycle- damn near impossible unless you have a test track in your back yard where you can sustain 60mph for 20 min., idle for 10, get to 60 in less than 20 sec., then start, stop, etc! Asinine!

 

I guess I'm buying $800 worth of exhaust ***************.

I guess I'm buying $800 worth of exhaust ***************.

 

Try the 2 spark plug antifoulers on the 02 sensor if you don't want to spend the money. It works a good percentage of the time. Drill one out so the sensor fits in it, stack them both on the sensor and reinstall. It pulls the sensor back out of the exhaust stream and fools it into thinking the converter works.

i beat this drum to death myself. Fron O2 sensor neds to be from a subaru dealer and the rear can be generic.

 

nipper

 

 

Sorry Nipper, I do also respect your expertise in various posts but I gotta disagree with ya on this.

 

Just installed my 2nd replacement (front) on the 96 OBW, 250K, both have been Denso's OE, not purchased thru Subaru. No problems...

 

http://www.sparkplugs.com/more_info.asp?AAIA=1269952&pid=2149

 

 

I'd try running a couple of tanks of another brand gasoline perferably 87 or 89 octane if you have been running higher octane. Also consider areas selling "winter blends" or "oxygenated" fuels can have an effect.

 

my .02 worth....

Edited January 4, 200917 yr by PAezb

Sorry Nipper, I do also respect your expertise in various posts but I gotta disagree with ya on this.

 

Just installed my 2nd replacement (front) on the 96 OBW, 250K, both have been Denso's OE, not purchased thru Subaru. No problems...

 

http://www.sparkplugs.com/more_info.asp?AAIA=1269952&pid=2149

 

 

and i can post 10 times as many links backing my point up, but i wont. i wont tell anyone to buy something i am not sure of. There is always someone who has good luck with something for the other 20 that do not.

 

nipper

Try the 2 spark plug antifoulers on the 02 sensor if you don't want to spend the money. It works a good percentage of the time. Drill one out so the sensor fits in it, stack them both on the sensor and reinstall. It pulls the sensor back out of the exhaust stream and fools it into thinking the converter works.

I would............ BUT, when I changed the rear one last time, it pulled the threads out with it. Then, I cross threaded the tap back in...... Oh the humanity!

I would............ BUT, when I changed the rear one last time, it pulled the threads out with it. Then, I cross threaded the tap back in...... Oh the humanity!

 

Maybe that's the small exhust leak nipper mentioned early.

Could be, but I cranked it in there pretty good. I'm sure the hole was small enough to get clogged with rust fairly quickly.

Could be, but I cranked it in there pretty good. I'm sure the hole was small enough to get clogged with rust fairly quickly.

 

Not with exhaust pressure blowing it out.

 

Honestly, a leak right at the OS sensor is VERY likely to cause a CEL.

I have a 06 baja with a p0420 light also with 18530 miles and been coming on since 15000 miles it has not been short tripped and only driven on vacations so seems to me this is a subaru problem because I've seen this on lot of 2.5 wagons

I have a 06 baja with a p0420 light also with 18530 miles and been coming on since 15000 miles it has not been short tripped and only driven on vacations so seems to me this is a subaru problem because I've seen this on lot of 2.5 wagons

 

try running some higher octane gas through it. That's what I have done before. A lot of it has to do with the crappy gas that we have now! The code means catylist efficiency below threshold

I have a 06 baja with a p0420 light also with 18530 miles and been coming on since 15000 miles it has not been short tripped and only driven on vacations so seems to me this is a subaru problem because I've seen this on lot of 2.5 wagons

 

Just take the 06 back to the dealer and let them fix it. It's under warranty.

It sound like You have a combination of problems. First: the O2 sensor bung. Second: the O2 sensor wiring.

 

If the O2 sensor bung came out. You need to get it sealed. They are normally welded to the pipe.

 

O2 sensors are VERY sensitive devices. Very sensitive to resistance. Any added resistance can knock the sensor out of its acceptable operating range. If the wiring is compromised. It could very well be adding resistance, and be causing Your problem.

It sound like You have a combination of problems. First: the O2 sensor bung. Second: the O2 sensor wiring.

 

If the O2 sensor bung came out. You need to get it sealed. They are normally welded to the pipe.

 

O2 sensors are VERY sensitive devices. Very sensitive to resistance. Any added resistance can knock the sensor out of its acceptable operating range. If the wiring is compromised. It could very well be adding resistance, and be causing Your problem.

 

 

what he said.

the dealer just resets and said it's ok I think it is set wrong and needs to be reflashed with more range

So here's the scoop.... I don't need no stinking catalytic converters!

 

2 weeks ago, I cleaned the MAP/ITS, put a new PCV valve in, and cleared the code. The CEL has been out for the past 2 weeks, and, today, I passed MD's Vehicle Emissions Inspection Program! The state got their $14, and I get to drive the Outback for another 2 years.

So here's the scoop.... I don't need no stinking catalytic converters!

 

2 weeks ago, I cleaned the MAP/ITS, put a new PCV valve in, and cleared the code. The CEL has been out for the past 2 weeks, and, today, I passed MD's Vehicle Emissions Inspection Program! The state got their $14, and I get to drive the Outback for another 2 years.

I love happy endings.