98 355, fabspeed headers, test pipes, tubi and slow down light

I had hyperflow cats which I removed and replaced with fabspeed test pipes. When driving the car there is no slow down light but as soon as I get into traffic or a very slow cruising speed the slow down light starts flashing. I'm assuming the test pipes are doing nothing to dissipate the heat and the temp sensor (thermocoupler?) is getting a high reading because of that. Will this cause me any issues? Are there an fixes?

Thanks
Ryan