I just installed a cobb catted downpipe with a borla hush turbo back on my '06 wagon and I can't drive my car tonight :mad: ! When I removed the O2 sensor from the stock front midpipe, it was extremely tight, every turn was the same tightness as the last. I PB blastered the snot out of everything before even attempting an install and this is my 3rd downpipe install. But after I got out the O2 sensor, I discovered that it was stripped in there from the factory! It looks like there is a weld ball between the first 3-4 threads and I need to wait for the morning to go to my suby dealer to pick up a new O2 sensor. I just needed to vent.

Anyways, the Cobb downpipe looks awesome, has perfect fitment and XX Tuning was great to deal with and they were local so I was able to pick up everything today.

-Jason

Sucks about the o2 sensor...but the wagon will rock Tommrow....
Hopefully you got some install pics and def some pics of the final product?
if so......well...post theM :)

I wouldn't get a new rear O2 sensor - you'll probably still get the P0420 cel, even with a high flow cat. Just get the electrical fix and plug the hole with a bolt.

no problems getting a cel with a dp on the 06 atleast so far and if you get a cobb ap the stage 2 map deletes that cel anyway so its all good.

how much for a rear O2 sensor? any other 06 owners have the same problem with the rear sensor?? If its a common thing, i will order one before doing my exhaust upgrade.

$149.99... One in the state of CT.

-Jason

I've done 3 downpipes and every single one of them stripped the rear 02 sensor. The factory really sucks at getting them in straight.

No worries though just get yourself a nice big breaker bar to put on the end of your socket and when it comes out just re-use it.

The threads on the 02 sensor are softer than the threads on the inside of the downpipe and you can easily rethread it. I did it everytime and although it's not the easiest to get in and out, it does go back in..and it seals...and works fine. This does not damage the threads on the downpipe...at least in my experience.

Certainly cheaper than 150 bucks + tax.

mine came off, no problems

woot. thanks a ton! good info!

no problems getting a cel with a dp on the 06 atleast so far and if you get a cobb ap the stage 2 map deletes that cel anyway so its all good.
It may supress the cel, but if you have to go for emissions, I think it will still show a "not ready" signal. It will only be ready if it is at least getting some signal from the O2. If he gets the electrical fix, this would be a lot cheaper than a new O2 sensor.

man thats how my car was....we had to weld mine to my new downpipe

I stripped mine as well. A replacement cost $129 here in Nebraska.

BTW, the ECU doesn't use the rear O2 for input for fueling except to lean the mixture over a very narrow range if it sees too much fuel post-cats.

It may supress the cel, but if you have to go for emissions, I think it will still show a "not ready" signal. It will only be ready if it is at least getting some signal from the O2. If he gets the electrical fix, this would be a lot cheaper than a new O2 sensor.

The Cobb maps don't surpress it they change what is acceptable. I have a Bosal dp with no o2 sensor and passed NY OBII emissions testing with absolutely no problems.

I've done 3 downpipes and every single one of them stripped the rear 02 sensor.Hmm, I've done a bunch of DP and I've never had one stripped :o

The Cobb maps don't surpress it they change what is acceptable. I have a Bosal dp with no o2 sensor and passed NY OBII emissions testing with absolutely no problems.
So, your O2 sensor is completely disconnected?

If so, some states allow for a certain number of "not ready" sensors before they fail you.

Ive had them get stuck on customers cars several times, makes an easy downpipe job a real pain. I usually heat them with the torch and they come out then rethread em

Actually I think I did not read carefully enough, only my front O2 sensor is disconnected. Since I am still running my third cat my rear O2 sensor is still in place.
All ready codes were fine. No errors or not ready codes with Cobb stage 2.

Actually I think I did not read carefully enough, only my front O2 sensor is disconnected. Since I am still running my third cat my rear O2 sensor is still in place.
All ready codes were fine. No errors or not ready codes with Cobb stage 2.Your car couldn't pass with the front oxygen sensor disconnected.

Mechanical CEL fix FTW.

Ok, then maybe I am confused! Where exactly is the front O2 sensor?

I just had my car inspected 2 days ago. I have a Bosal shorty downpipe and my third cat is in place and it passed with no problem.

Ok, then maybe I am confused! Where exactly is the front O2 sensor?.Doh!

You most likely pulled your EGT sensor from the uppipe. The AccessPort stage 2 will kill the CEL codes associated with that sensor. It's connector is just below that of the front A/F sensor connector.

There's no way you're running happy without your front A/F sensor.

Ok, then maybe I am confused! Where exactly is the front O2 sensor?

I just had my car inspected 2 days ago. I have a Bosal shorty downpipe and my third cat is in place and it passed with no problem.

Front O2 sensor is in the manifold. aka factory headers on the Passenger side.

-Jason

Same problem with my 06 TR I eventually used my jack handle to put on the end of a wrench to make a 4 foot breaker bar. got it off, but then noticed it was either stripped or welded from factory. $165 later. a new o2 sensor.

Better late then never....

I had about 6,000 miles on my 2006 WRX Wagon, and up popped a CEL. Took it to the dealer and it turned out to be the O2 sensor after the cat. When the part came in and they pulled the old O2 sensor they found the same thing you did, stripped melty looking threads, and the new sensor wouldn't thread in.

They replaced the entire cat section and sensor under warranty and loaned me a Tribeca for the week while they waited for the part to come in.

When I replaced my DP I had the same thing happen. I ended up having my mechanic try to free it and it ended up stripping so I just put in an 02 bung and let my AP take care of the CEL's. When I went to emissions here in MA I got 2 NR's (1 for CAT and I forget the other one) so they failed me. Once I put in an 02 sensor and reset my ECU I had to drive around a bit for it work.

If you can wait order your 02 sensor from http://www.automedicsupply.com/. Mine cost $50 if you rewire the harness. If you get a new harness it's like $90.

u can fix the stripped threads using a hack saw

Whenever I take out an 02 sensor, I always torch the area first to heat it up, and then use my trusty 02 socket. It's fun. :p

my 06 was the same, the 02 was SOOOOOO tight, i put something besides pb blaaster on it, with in seconeds it was like it never had a problem. i didnt see any welds. and if it was welded, wouldnt it of striped the DP going in?

Whenever I take out an 02 sensor, I always torch the area first to heat it up, and then use my trusty 02 socket. It's fun. :p
dosent heat make the metal expand, therfor making it tighter?

dosent heat make the metal expand, therfor making it tighter?

Heat makes everything expand... it also makes the rust lose the H20 component thus making space for the threads...

-Jason

The bung will expand at a greater rate than the oxygen sensor, thus allowing it to be removed easier.