[Thunderchild]

I was out this weekend and my dashboard lit up. Check engine light, the AWD light next to it and the cruise light blinking. I took it to my mechanic and he pulled the codes. Said the CC is going bad. It did drive the same when I took it too the shop. He says it will be between $1500 and $2800. He is going to check the pricing for me. He told me he only uses Subaru parts but if I want to use something different I can give it too him and he will put them on. Does anyone know of any aftermarket converters I can order? Thanks in advance!!

 

[subiesailor]

This is the classic Fleecing of Subaru owners. First off the failed O2 sensor normally triggers an engine light thats it. Not other lights + engine light.

The O2 sensor is the first thing to replace front one is subaru brand the rear one can be generic. I replaced the front one first and in my case My front cat was done due to damage three years earlier. Which case I had a local ma and pa exhaust shop weld in a new cat for $150 put in a new O2 for $300 and the car was perfectly fine for another 40K then I sold it at 180,000. The bolt on subaru parts will cost you major money and chances are all you need is the O2 sensor anyway.

 

[Thunderchild]

Thanks for that SS. Just what I needed to hear. I am going to have him check the O2 sensors first. I will probably have them replaced.

 

[idosubaru]

This is awful and the converter doesn't need replaced. Hmm...I'll be in Westminster MD in a few weeks - I'll fix it for $500, deal?

You can type in P0420 in google and read for years about this debacle of an issue.

Catalytic converters last the life of the vehicle unless something abnormal compromises them (very rare)...so slow down. 1980's Subaru's are still passing maryland emissions just fine on their original converters (if they haven't rusted off!). Subaru converter failure is extremely rare and about the last resort, not the first.

First - you should tell us exactly what codes lit up.
Although I'll just tell you that one of them was the P0420 code that likely popped it's ugly head.

This issue is due to some very tight tolerances (too tight) in the monitoring algorithms. All sorts of miniscule things can set off the P0420 code...the tolerances are just plain stupid and not worthy of the real world - they're impractical and don't even effect emissions exactly. The vehicle I can guarantee you would pass Maryland emissions sniffer tests...they just won't do it with the CEL on, but it would physically pass - i'd bet $1,000 on it...well more than that, because I'm right.

The $5 fix is the smartest thing to do. But first you need to make sure there are no exhaust leaks, the engine is in proper tune (have plugs/wires ever been replaced?), and the O2 sensors aren't the culprit, and it is indeed the 0420 animal.

If you're not up to the $5 fix or reading about this debacle of an issue then pay Subaru to do the test that have for this....make sure they don't just tell you to buy a converter - make sure they do the proper computer/smoke/oscilloscope test - the real deal, whatever it is called you can probably google that too. they have a very rigorous way of narrowing down this issue rather than just throw $2,000 at this thing.

aftermarket converters can cause the P0420 code to light up and also may rust out quicker depending how cheap you go. Heck - i've seen new Subaru converters still have the code comeback - because it's never the code. Often replacing the converter fixes it only because they also replaced some leaking gaskets, a lazy O2 sensor, or heat shields in the process or the new converter just barely made up for some other issue...when in reality the converter wasnt' the problem at all.

correlation does not mean causation...

in the end the $5 O2 extender is what intelligent rational, practical people are doing. do it.

 

[subiesailor]

Regardless of what the mechanic says - get the code the car is throwing. The o2 sensor code is pretty famous around here on the forums you can search on O2 sensor and get it. I can't recall the exact code P40 something or other.

If the shop keeps blowing smoke at you find another one. The O2 sensor is very simple takes about 5 minutes to swap - looks like a spark plug with a wire on it just screws into the exhaust up front just before the front cat. Simple fix but the O2 sensor is like $200 bucks or more. Not cheap but far cheaper than a full replacement of the cats which are probably fine.

Also if the cats are for sure done I would also check in with Subaru directly given they do in some cases have a replacement policy for owners who have early failure on some of their models. Subaru is known for doing the replacement at no cost so worth looking into.

 

[subiesailor]

Also a very wet situation can trip up this system if you get lots of moisture or water in the cat. In my case I cracked the Y pipe (caused by hitting a hard chunk of ICE that fell off a truck infront of me) right at the joint just before the front CAT so every time we had a really wet rain storm I got the engine light and P04 code. After a few days it would dry out and the light went off. I drove it like this for 3yrs before the light simply remained on. Then I bought the new Ypipe $300 online subaru parts store took me about 40 minutes to pull the old one and replace it - then I did the O2 and the ma and pa cat replacement given mine was actually damaged. The rear cat was fine. Car must pass CA smog which is pretty strict zero issues with that for another 4yrs

 

[plain OM]

I wonder if it has nothing to do with the engine/emissions or P0420. I raise this because of the AWD light. (I'm not aware of any engine trouble codes that cause the AWD light to come on.)

The AWD light might be indicating a fault in the transmission area. In these 3rd generation cars, when the TCM detects a fault, in addition to setting it's own transmission codes, it sets a P0700, which is "Transmission Control System (MIL Request)". This is sent to the ECM requesting that the CEL be turned on. Of course, we all know that when the CEL is on, the cruise control is disabled and so the Cruise light will also flash.

As has already been said, we need to know the codes that were found (and might still be stored) in the OBD II memory. Also because some transmission codes are not readable by many OBD II readers, they can be missed. However, there are more sophisticated readers/scanners that can access the Subaru-specific transmission codes, including the dealer's Subaru Select Monitor. In addition, there's a DIY method: See http://www.subaruoutback.org/forums...9-how-read-diagnostic-trouble-codes-dtcs.html

Read the codes, and then you will have a much better idea of where the problem originates, and you might just avoid unnecessary work, and replacing parts that don't need to be replaced.

 

[Thunderchild]

Hey all. Thanks for all the great info. In fact it was the P0420 code that was thrown. My mechanic checked the O2 sensors and said they were fine. As for the moisture, I was driving behind a truck and it was raining like crazy. I wonder if the extra water the car was probably ingesting had something to do with it? I had him reset the code and the light's are off. I have driven it for 100 miles now and the light still has not come back on. When I had my Durango, it would throw a check engine light from time to time when I got some bad gas. I would run it out and put in a new tank and the light would vanish. I filled the car last night before I took it on a run to see if the light would come back on. It did not.

Plain OM:

The transmission and all other AWD parts are fine. No issues there.

Grossgary:

What is the $5 fix?

He gave me a price to replace the cat. He says it is the front one that is connected to the Y pipe. $1040.00 is what he quoted me. I think I am going with you guy's and just keep an eye on it for awhile. If the code comes back I am just going to have him reset it. If it is not back on after 100 miles, I do not think it will be back on.

 

[Thunderchild]

This is the classic Fleecing of Subaru owners. First off the failed O2 sensor normally triggers an engine light thats it. Not other lights + engine light.

The O2 sensor is the first thing to replace front one is subaru brand the rear one can be generic. I replaced the front one first and in my case My front cat was done due to damage three years earlier. Which case I had a local ma and pa exhaust shop weld in a new cat for $150 put in a new O2 for $300 and the car was perfectly fine for another 40K then I sold it at 180,000. The bolt on subaru parts will cost you major money and chances are all you need is the O2 sensor anyway.

Hey SS, where did you get that Cat from? Did you order it online?

 

[subiesailor]

Hey SS, where did you get that Cat from? Did you order it online?

Local shop they have two lifts outside they do custom exhaust systems etc. Simply drove by pointed out the front cat said how much to replace it - the wife looks at it says $150 go have lunch at the deli over there come back in 30 minutes.

They cut out the old one - welded in the new one clean job zero issues for the rest of the time I had the car which was another 40,000 miles

 

[Thunderchild]

Holy moly!!! That was a great job there. I looked on the SubaruGenuineParts.com website and priced one just in case. More than $200.00 cheaper than the shop said. If needed I will buy the parts and have them install. Thanks again.

 

[subiesailor]

By the way that is how most people have exhaust work done buying expensive factory bolt on parts is a pretty rare case.

Given your experience with possible water intrusion I would inspect the joint at the "Y" in the y pipe as that is where I cracked mine after hitting debri on the road. This is just infront of the front cat and when the roads are really wet the Cat ingests water and road grime and will cause the Exhaust readings to trip the engine light on the dash.

 

[cardoc]

http://www.subaruoutback.org/forums/66-problems-maintenance/49537-p0420-diag.html

 

[Thunderchild]

By the way that is how most people have exhaust work done buying expensive factory bolt on parts is a pretty rare case.

Given your experience with possible water intrusion I would inspect the joint at the "Y" in the y pipe as that is where I cracked mine after hitting debri on the road. This is just infront of the front cat and when the roads are really wet the Cat ingests water and road grime and will cause the Exhaust readings to trip the engine light on the dash.

I will do this when the weekend get's here. Thanks again for the great info!!

 

[Thunderchild]

http://www.subaruoutback.org/forums/66-problems-maintenance/49537-p0420-diag.html

I was reading this post Cardoc. Thanks for the info.