Info z wikipedii nt. zwyklych sond:
The sensors only work effectively when heated to approximately 316 °C (600 °F), so most newer lambda probes have heating elements encased in the ceramic that bring the ceramic tip up to temperature quickly. Older probes, without heating elements, would eventually be heated by the exhaust, but there is a time lag between when the engine is started and when the components in the exhaust system come to a thermal equilibrium. The length of time required for the exhaust gases to bring the probe to temperature depend on the temperature of the ambient air and the geometry of the exhaust system. Without a heater, the process may take several minutes. There are pollution problems that are attributed to this slow start-up process, including a similar problem with the working temperature of a catalytic converter.
A dalej:
Sensor failures
Normally, the lifetime of an unheated sensor is about 30,000 to 50,000 miles (50,000 to 80,000 km). Heated sensor lifetime is typically 100,000 miles (160,000 km). Failure of an unheated sensor is usually caused by the buildup of soot on the ceramic element, which lengthens its response time and may cause total loss of ability to sense oxygen. For heated sensors, normal deposits are burned off during operation and failure occurs due to catalyst depletion, similar to the reason a battery stops producing current. The probe then tends to report lean mixture, the ECU enriches the mixture, the exhaust gets rich with carbon monoxide and hydrocarbons, and the mileage worsens.
Leaded gasoline contaminates the oxygen sensors and catalytic converters. Most oxygen sensors are rated for some service life in the presence of leaded gasoline but sensor life will be shortened to as little as 15,000 miles depending on the lead concentration. Lead-damaged sensors typically have their tips discolored light rusty.
Another common cause of premature failure of lambda probes is contamination of fuel with silicones (used in some sealings and greases) or silicates (used as corrosion inhibitors in some antifreezes). In this case, the deposits on the sensor are colored between shiny white and grainy light gray.
Leaks of oil into the engine may cover the probe tip with an oily black deposit, with associated loss of response.
An overly rich mixture causes buildup of black powdery deposit on the probe. This may be caused by failure of the probe itself, or by a problem elsewhere in the fuel rationing system.
Applying an external voltage to the zirconia sensors, e.g. by checking them with some types of ohmmeter, may damage them.
Czyli wynika z tego, ze sonda jest podgrzewana tylko na poczatku z przyczyn ekologicznych:). Potem juz podgrzewana jest tylko przez spaliny. A wiec jakakolwiek imitacja grzalki powinna dzialac i mysle nawet, ze nie musi to byc potezny opornik bo sonda jest mala a wiec rozgrzanie do 316 st to mala dawka energii.
Natomiast ciekawsza jest dalsza informacja o bledach sondy, z ktorej wynika, ze sonda bez grzalki gromadzi sadze i z czasem zaczyna odpowiadac z opoznieniem. Potwierdzaja to moje dawne wizyty u gazownika, ktory skarzyl sie ze sonda pracuje wolno, a po zmianie na sprawna uzywke znacznie sie poprawilo. Moze sie da jakos te sadze usunac. Poza tym sonda moze sie po prostu zuzyc po 160k km (o ile sprawna byla grzalka) jak bateria:)
