I have a 2000 Toyota MR2 Spyder with 57,000 original miles. 

Last week I was driving around and ran into a sizable fuel spill at a diesel fueling station. Road crews and police were directing traffic and everything. But the stench of diesel was thick in the air, and it lingered in my cab for a little while after I drove away.

Within about a mile my check engine light came on. My OBD II scanner showed two instances of P0155. I checked all my fuses and looked for any obvious wiring issues and didn't notice anything. So I cleared the codes and have been driving the last couple days without issue.

My question is, is it possible for fume-rich air to cause a false P0155 code? Or is it most likely a coincidence, and a good idea to replace both Bank 2 sensors? Or something else I'm unaware of?