I have had the TST box on for 8 weeks now, with only the usual codes p0606, p0336 showing up. Today, The truck started shuddering a bit at 60mph. got it off the road and checked for codes and the p2141 and p0202 show up. I unplugged the middle harness and plugged it back in again, then all was well... ... for about 20 miles. Started to do it again. So, what should I check or do to fix this ?? Thanks in advance JP