In the past there was only one place to get oxygen sensors for the WRX... the dealer. If you went to an auto parts store you would probably get something that didn't have the right wires or you had to cut your old harness off and soldier it in. Thanks to Denso this isn't the case anymore!
Normally, we wouldn't be interested in selling something that cost roughly the same as an OEM piece except when there was an added benefit. The new Denso oxygen sensors have such a benefit... the ability to handle leaded gas!
DENSO Oxygen Sensors were rated as TWO TIMES MORE RESISTANT to silicone and lead poisoning.
Here are some more of the features of the Denso sensors. Fluorine Rubber Bushing: Protects the internal components of the oxygen sensor against water and corrosion.
Double-Protection Cover: First developed by DENSO, the double-protection cover assures quick response time by maintaining proper unit temperature in the ceramic element and protects the ceramic against outside lead and silicone poisoning. Available on all DENSO heated sensors.
Stainless Steel Housing: Rugged, watertight stainless steel body resists corrosion and contamination.
Porous tetrafluoroethylene (PTFE) Filter: This highly durable, heat-resistant material helps maintain the oxygen sensor's optimum performance. Porous tetrafluoroethylene allows atmospheric oxygen to enter the sensor without permitting water or engine contaminants to seep into the casing.
Aluminum Oxide Trap Layer: A DENSO exclusive, this specially designed aluminum oxide coating keeps silicone and lead outside the ceramic element and prevents silicone poisoning or damage to the platinum electrode.
Fits 2004-2007 STI and 2006-2007 WRX