Directly from Seafoam.

[SoSideways]

Originally Posted by nismosis

i did the seafoam in the vacuum tube thing on my 04 350z, no o2 sensor problems or any other problems for that matter... i really dont see why everyone thinks that it will mess something up... maybe it was a bad/cheap batch of o2 sensors from the manufacturers are the reason people are having problems? i dunno... but i had success with mine... it was fun too because on mine, a ton of white/grey smoke came out of the exhaust and everyone was looking over at my car... lol

Did you even read the thread?

S14DB took a pic of his O2 sensor AFTER he did the Sea Foam treatment, and next to it was a brand new O2 sensor.

Look at it.

Does it look like it's normal? No.