I have a 2006 MX-5 "sport" model, about 40,000 miles. It has a 6 speed manual trans, and have done the following engine mods over the years: Cobalt cold air intake, K&N air filter ( in2007), engine oil cooler (2008), short throw shifter (2008), OBX header(2009), and Magnaflow cat back exhaust (2011). After I installed the header, the two O2 sensors went right into the same location as "stock", the code P0139 came up, (Rear h2os circuit problem). I then installed a 02 sensor device that moved the sensor back a bit from the regular gas flow; the code still appears.
I then installed the magnaflow cat back exhaut, and within 40 miles additional codes P2096 and P2097 were "thrown".
The combination of all the mods has made the engine scream. Each mod was done with months/years between, and I could notice by "seat of the pants" driving the car rev'd better and higher with each additional mod seemed like more power, and occasionally get a chirp out of 3rd and 4th gears on spped shifts. Below are the codes from my scantron code tool.
P2096 Post catalyst Fuel trim too lean, Bank 1
P2097 Post catalyst fuel trim too rich, bank 1
P0139 o2 sensor circuit slow, response 1/2
Are there any recommendations to clear the codes, perhaps upgrading/reprogramming the ECU? Perhaps relocating the O2 sensor to behind the catalytic? When I clear the codes with the scantron, they come back within 50 miles.
If an ECU, any suggestions for make?
Thank you for your reply.
2006 MX5 sport, black, in Maryland.
2006 MX-5 Sport, 6 speed manual, black on black