My engine light came on today and the code is P1296. I did a general scan of the engine to make sure the TBB and other hoses were attached. I noticed a crack in the Coolant Expansion Tank with a very small amount leaking. I am wondering if this crack is allowing air into the cooling system causing the P1296? (Before I go out and buy the coolant temp sensor and 02 sensor). If not would the CTS and 02S replacement fix it?

Also, I will have to replace the Expansion Tank regardless now and would appreciate any advice as to where a good place to pick up a new one would be.

Thanks in advance!