P0135 and Longtubes

[AntonioMiller]

Hello, I'm currently having some trouble with a P0135 on my 06 MGT that's been stuck ever since I got my long tubes, and now I'm about to be due for emissions and can not get rid of it. I have replaced the front o2s twice, and I also tried setting the P0135 to no error reported, just to get a lean code right after. I currently have both o2s in and was wondering if there's any way I can fix that in hp tuners? I'm very new to hp tuners so any help would be appreciated.

[4wheelinls1]

P0135 is a Heater circuit fault in Bank 1 sensor 1, did you extend the harness or fit extensions due to the sensor location?