I have 2007 corolla and I installed racing heading. Since then it gives P0420 code. I have tried to install an oxygen simulator but simulator gives me P0136 and P0137. I also heard add a spacer between exhaust and O2 sensor could fix this problem. What should I do? My tag has expired and I really need to pass emission test asap. Help plz!
ps my simulator is from http://www.ubertechnics.com/o2_simulator_2.5.aspx