Uhm... O2 sensor is part of emissions equipment and has it's very own warrantee through CA - If you're under 3/50 it should be covered by SOA. Especially since it doesn't sound like you have any mods that would affect the O2 sensor.

Just cause there are people that are abusing their warrantee doesn't mean your's is less effective and I would call SOA and remind them of that fact. O2 sensors fail - it's the nature of the beast. But they're also a warranteeable part. I would call Bruce and ask him exactly why SOA denied the warrantee.

 

I'll disclaim this by first saying that I agree that, for the most part, power and reliability are on opposite sides of a sliding scale. And that if you're boneheaded enough to turn the power to eleven without addressing strength/reliability then you get you what you deserve - Case in point 18psi melting a motor. I don't think SOA should have bought him a new motor.

However, I am going to have to play devil's advocate here for just a little bit. I've seen a lot of good 02 sensors replaced by competant technicians. If the scanner says 02 sensor biased lean, often the 02 sensor is replaced without checking tail pipe emissions or sensor voltages. 02 sensors are also fairly sturdy little buggers. Sure, a little coolant will generally nuke one. And excessive heat (>1500 deg f) may cause cracking. But I've also seen quite a number of 02 sensors fail in new, stock vehicles. And to say that a modified up-pipe and a catback exhaust caused the failure in the 02 sensor leaves me a little cold. Even more so because cars sold in California must carry a 3 year/50,000 mile warrantee on emissions related parts. Since 02 sensor is critical to a feedback system and closed loop operation - I'd say it qualifies. I stand by saying "Call SOA".

There are some details left out. Which 02 sensor failed? How was the sensor diagnosed? What was the actual code pulled from the computer and was there freeze frame evidence of abuse? And is this a common sensor failure?

I ask the last question because even though there has been a TSB regarding wheel bearings - there's still some dispute about the cause of failure. SOA is also reported as saying that sealed bearings are "wearable items"... But I digress.

I think that abuse is generally a fairly clearly defined term. I don't necessarily believe that fanker's case is abuse.

The only remaining question on my mind (in terms of abuse) is whether or not uppipes are raising exhaust temps beyond 1500 degrees f. Is anyone actually seeing this happen??

Edit added here:
Regarding exaust temps. I'd have to say that every O2 sensor I've dealt with is from a NA engine. The documentation I've got says that they're generally good to about 1500 degrees f. In looking through the factory boost forum I see people talking of temps in the 1450's (downpipe) and 1650's (uppipte) for stock motors... I would hope that either Subaru Engineers are using a higher grade 02 sensor or has it placed far enough downstream that EGT's are low enough.

 

I don't see why a shop would refuse to work on a car that already has missing smog components. As of 2003 it's illegal for a shop to modify, remove, or disconnect a smog component though. It's also illegal for a non smog certified shop (and technician) to perform smog related repairs after a failed smog for compensation. But if the cars smog is already missing the car is not unsafe - it just wont pass a smog inspection.

It's generally in the shops best interest to not work on an unsafe vehicle without making the vehicle safe first. IE: your alignment example. And really, with unsafely worn tires I doubt the alignment would be perfect - or at least solve the reason you brought the car in for alignment in the first place. (pulling??)


Still, regarding the O2 sensor failure. If we're talking "rear" as the final post cat O2 sensor, I don't see how an uppipe or cat back exhaust would cause the failure. If Bruce's decision to not cover the O2 sensor is based on SOA's approval, I would ask him to find out exactly why they are denying warrantee coverage. If it was Bruce's call, I would ask him why he felt that your mods caused that particular O2 sensors failure (and not any other O2 sensors). I'll also have a chat with a friend and discuss why a bad rear O2 sensor would throw a P100 code. Can you be more specific than "rear" 02 sensor?