3.0R Cats bad at 24k?

So, my 2009 3.0R threw a cat efficiency code. Turns out one of the three cats failed the flow test, one is breaking apart (can hear rattling chunks of ceramic in the pipe) and the third will be replaced because of peer pressure. Thank God for warranties.

 

The car has less than 24k miles. I bought it used and I don't know what the previous owner may have done, but that seems like a pretty dang short lifespan for the cats.

 

I know Subaru cats are not known for being immortal, but this seems a bit worrisome. Anybody else had early-onset cat issues with their 3.0R? (or 2.5i or GT...)

 

Other than this, the car is great. I've had it about two weeks. Love the smoothness of the motor.

I assume that you don't have any other codes, but I would recommend you to look at the spark plugs to see if they are all alike or if they vary in color. If they vary in color it may be that you have a problem with the injectors or an air leak causing imbalance between the cylinders and subsequently more strain on the cats. A bad O2 sensor can also be a culprit even though there is no code, and the only way to know is to do a test on the sensors or replace them.

 

Also do a compression test when you are at it. It can tell you if the engine is good or if it is developing a problem. Also keep an eye on the oil consumption.

i would suspect it was just a fluke and there was a manufacturing defect though ^^

Well the cats shouldn't fail for the "life" of the car. For a 3.0R to have a physically failing cat means you have a serious upstream issue ( somewhat likely) or a poorly constructed cat ( somewhat likely). For the Substrate to be failing apart at this point suggests the latter. The good part is you can get it replaced FOR FREEE!!!!!!!!!!!!

 

As long as it is under 80k miles (This it the warranty period for emission equipment and the cat is the major player)

No other codes. The grid disintegrating leads me to believe there was a defect in construction, but it does make me worry a little... I agree that upstream there could be something going on. I don't know what the previous owner ran through the motor, either.

A cat fail can be caused by it being overheated and if it gets too much unburnt fuel it will overheat. A defect in construction would manifest itself rather soon, and it's not that common since cats are relatively simple in construction.

 

But just checking the spark plugs would provide valuable information to the general condition of the engine and it would be good to check so that you don't burn another cat.

I spoke with the service writer, he told me that once the cats are replaced and everything is back together, they'll do some further diagnosis. I'll keep you posted. Thanks for the tips, ehsnils.

It's back together. SOA replaced all three cats under warranty. In testing afterwards, everything looked ship shape, ran like a top, everything in spec. So, I'm wondering what the previous owner ran through the engine to do such damage to the catalysts. I haven't pulled the plugs yet to have a look. I'll see if I can get to that this weekend.

Can be a good idea.

 

Even if the car seems to run fine and conforms to manufacturer specs there may be some improper balance between the injectors, and the exhaust is then mixed and cat-processed which causes what goes out through the tail pipe to look good.

 

Of course - driving style is also something that can kill a cat, and short driving distances when the cats almost never ignites but just are filled up with contaminants can be a killer too - and then they ignite and tries to burn off everything at once causing the cats to overheat.

 

A tune by a good tuner can also be a good thing. The dealer usually looks at the patterns and emissions figures for a defined driving cycle and if you drive outside that pattern - extreme granny or lead foot then all bets are off. A good tune may even improve your mpg.

You should of upgraded the headers, run exhaust, and run catless it would of sounded pretty beast.

You should of upgraded the headers, run exhaust, and run catless it would of sounded pretty beast.

 

Yeah, it would sound cool, but I want to maintain my warranty.

 

The odd thing is, these failed at 24k. One was actually breaking apart. I am reading up on what may have caused this and have found lots of different possibilities. If anybody has more ideas on what to check, please share them!

 

The question I have for the moment, however:

I just changed the oil in the 3.0. (I've had the car less than a month and I don't know what crappy oil was put in there, so I changed it for peace of mind and put some Rotella T-6 in.) When I was changing it, I noticed a noticeable fuel odor both from the oil and especially on the oil cap. I thought this may be a product of the testing the dealer needed to do after installing the new cats so didn't think much of it. Oil was warm when changing. I did not see a rainbow sheen of fuel in the drain pan.

 

Anyway, I've put maybe 100-150 miles on this oil now. After a 40 mile drive home last night, I decided to sniff the oil cap when I got home. I smelled fuel again. Am I correct in thinking after a longish drive, it should have burned off? Do the 3.0 motors have fuel dilution issues? A few people on BITOG seem to think so. I've never noticed a fuel odor like this on any other car I've had.

 

I've got a Blackstone kit on the way to check the oil in the motor after a month or two.

 

Any thoughts on this would be appreciated. Thanks much.

I've had a 3.0 for over two years, and no fuel odors or seeing fuel mixed in the oil.

There's a small number of people who report clogged cats on 2.5i. Its almost always very low mileage vehicles that are never driven long enough to properly warm up the cats. 24k on an 09 isn't all that low, but may still have been a factor.

Yeah, it would sound cool, but I want to maintain my warranty.

 

The odd thing is, these failed at 24k. One was actually breaking apart. I am reading up on what may have caused this and have found lots of different possibilities. If anybody has more ideas on what to check, please share them!

 

The question I have for the moment, however:

I just changed the oil in the 3.0. (I've had the car less than a month and I don't know what crappy oil was put in there, so I changed it for peace of mind and put some Rotella T-6 in.) When I was changing it, I noticed a noticeable fuel odor both from the oil and especially on the oil cap. I thought this may be a product of the testing the dealer needed to do after installing the new cats so didn't think much of it. Oil was warm when changing. I did not see a rainbow sheen of fuel in the drain pan.

 

Anyway, I've put maybe 100-150 miles on this oil now. After a 40 mile drive home last night, I decided to sniff the oil cap when I got home. I smelled fuel again. Am I correct in thinking after a longish drive, it should have burned off? Do the 3.0 motors have fuel dilution issues? A few people on BITOG seem to think so. I've never noticed a fuel odor like this on any other car I've had.

 

I've got a Blackstone kit on the way to check the oil in the motor after a month or two.

 

Any thoughts on this would be appreciated. Thanks much.

 

I would certainly check the injectors in that case. If you have one that doesn't seal correctly but always leaks a bit or doesn't give a good fine spray but just pours the fuel into the cylinder you certainly can get that effect.

the car has 24k. If you start tinkering with injectors and spark plugs and you break something warranty won't help you.

 

Let the dealer inspect it.