Seafoam was first introduced in the marine world for cleaning the gunk out of a marine engine. It has been brought into the automotive world for cleaning the gunk out of a car or truck engine. Seafoam will help clean intake valves and pistons, reduce atalytic converter odors, restore power and pickup, and is oxygen sensor safe.
Seafoam will not clean or restore an 02 sensor. Many people take Seafoam's statement that "Seafoam is oxygen sensor safe" to mean that it will restore or clean 02 sensors. Seafoam will not clean or restore a worn oxygen sensor. Nor does Seafoam claim it will clean or restore a oxygen sensor.