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Catalytic -- how to diagnose left/right/rear on H6?


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Hi -- I am going to do vaccum check to diagnose if I have catalytic issue as it was suggested in the other thread. But H6 has 3 of them -- 1 in each sleeve of Y pipe and rear one right after Y pipe joint before the flanger to connect rear pipe. Of cause Subaru made it very easy to replace 2 of them -- left front one and rear one are on the same "pipe" whenever the right one is in the separate Y pipe sleeve... So -- no cheap "proper" solution. I am just curious how much OEM piece would cost... anyone has a part #s for 4S3BH806317652768?

 

heh - so, to diagnose, if I get vacuum readings characteristic to clogged CC -- which 1 (or 2 or 3 ;-)) out of 3 CCs would that be? it would be a shame to cut off the working one.

 

Should it be simply a "test" with rubber hammer and look for sounds?

 

should I get 1 Y pipe to disconnect from engine block at a time?

 

what is most common point of failure?

 

can water comming to muffler (when going under "waterline") get all the way to rear cat and damage it?

 

Thanks in advance

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If your cat is clogged it will be covered by the 100,000 emissions warrenty.

Those are gold words to please my ears, but I can't find support documents (and I need to rush since I am at almost 98k miles) -- the only reference so far is at

http://www.cars101.com/subwarr.html

which says only about

"Certain Legacy and Outback 2.5L 4 cylinders sold and registered in CA, CT, NH, NY, MA, MS, RI, VT with California Specification PZEV Emissions Extended defect warranty: 15years/150000 miles"

and I have 3L 6 cyl and do not have any extended warranty, and live in NJ (pretty much).

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Me too. It was a federal rule. I think they changed it form 100K to 80K when we weren't looking.

 

He is going to have to look in his owners/warrenty manual(propaganda) to see what it is for his car. That must have been a recent change, as i s see the super low emissions are now 150,000 ( i think, im not awake yet). That must have been the trade off.

 

nipper

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Just found this a few minutes ago - Someone posted a link on subaruoutback.org that explains exactly how to diagnose catalytic converters and O2 sensors. You'll need an oscilloscope, graphing multimeter, or similar.

 

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

 

Sounds like there are 3 cats on the H6. How many O2 sensors and where are they? If there's not an O2 sensor before and after each cat, it will still be difficult to pinpoint which one is bad (if any) with this method.

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