O2 Sensors

[bplaney]

I can't believe how much a full set of new O2 sensors costs. Is it possible to rejuvenate my existing ones? do they "wear out" by getting gunked up?

[intakerGS]

As the O2 sensor is based on a ceramic substrate and oxygen migration through it, also protected by a metal guard, it's not easy to get to the sensor and clean it. Second, you need to determine what kind of contamination is involved. This can be a carbon buildup, or blocked substrate by oil, coolant, gasoline etc.

Some heat the tip of a O2 sensor with a torch, crusting the carbon buildup. If lucky, the O2 sensor generates sufficient operating voltage for a given period. When the substrate is blocked (oil in general), you can expect incorrect operation, or none at all. It's considered impossible to remove this type of contamination with any cleaner. For this reason you'll never see 'refurbished' O2 sensors (and if you do, avoid them).

Just my 2 cents, take the dive..

[GuyTelefunken]

Answer: No. They wear out from heat, contamination, and/or age. The direct-fit models from oxygensensors.com are well priced and reliable. Walker or Denso are both excellent. I would stick with the same brand for all, if you're doing all of them. Avoid the "universal" type as they must be wired to your existing harnesses. Many times this comes back to haunt you later due to corrosion at the connection point. The direct-fit models are plug-n-play.

[bplaney]

Answer: No. They wear out from heat, contamination, and/or age. The direct-fit models from oxygensensors.com are well priced and reliable. Walker or Denso are both excellent. I would stick with the same brand for all, if you're doing all of them. Avoid the "universal" type as they must be wired to your existing harnesses. Many times this comes back to haunt you later due to corrosion at the connection point. The direct-fit models are plug-n-play.

OK, getting back to my original post - the price of these things - what on earth is the technical justification for O2 sensors costing so much? are they any more complicated than so many other commodity parts to manufacture? a PCV valve is cheap, but from a manufacturing standpoint, is it that much less difficult to manufacture?

[intakerGS]

O2 sensors with a heating element are in general more expensive to (mass)manufacture. It also depends on materials used, precision, electrical specs, respond-time, time-constant etc. For that reason OEM sensors are no doubt the best choice and within factory (ECU) specs.

There are 'cheap' or non-branded O2 sensors, often (slightly) out of factory spec, resulting in a slow 'warm-up' time, bad electrical respons etc, running your car rich or retarded, or create other problems in future.

[bplaney]

Can running the engine on regular gas (instead of premium) hasten the demise of the O2 sensors?

[intakerGS]

Nope, you can safely use regular gas from a known brand, without demising O2 sensors. Most engines run fine on regular gas, even Porsche (as they state this themselves).

Premium contains more octane, boosting power a bit (hardly noticable at all) and to prevent knock, plus some additives to clean the engine (not enough to be effective actually). So, if your car doesn't knock when accelerating, your OK.