Have a 2015 NX4510 HST. i got it with 225 hrs, now has 250hrs. it has done a regen atleast 3 times in 25 hours. i always try to run it above 2000 RPM. i have no warning or ECU Lights on. after about an hour of standard load (running 6ft brush hog) i start getting exhaust temp light, i have...