I'm having an issue with my 2016 LS. Getting the code P0420 and was told I needed a new front converter so I had it installed along with both oxygen sensors, map sensor, maf sensor, fuel rail sensor and flex pipe. Code was cleared and after many drive cycles came back on a few days later. Cleared again and is back on. Went back to the dealer and was then told oh your problem is the converter behind the manifold but the front one. If course the wanted to charge me another $1000 so I left. I went to a shop that strictly deals with exhausts and was told that on the Trax the converter behind the exhaust manifold would not give that code so not to waste my money. Can someone help. It's driving me nuts !