I recently had a problem with my 02 Monty sport bucking and jerking after discovering the problem I found out it was bad plugs and wire so I took care of that and the problem was solved. Before that I have the P0138 check engine code, bank 1 sensor 2, so the downstream passenger 02 sensor and it was always on. After a couple of key cycles the code went away and it hasn't come back on since. My question is that normal and is the 02 sensor still bad?