Aftr Emssn Inspctn,car at stop in gear shudders rpm goes very low. on 2006 Subaru Outback

Just had my car emssion inspct done . Now under load in gear the car shudders engine rpm drops to ~500 Repair Tech said State Emmsin machine wiped out engine codes and to drv 57-100 miles they will reset ?? any one heard of this ?? Thanks!

2 answers 1 comment
scan forcodes and post so we can adv
Hi the service tech who re checked it said there were " no " codes at all! I believe this is what he based this diagnosis on. I have since driven nearly 90 miles with no change so far. thanks
Its a Drive-By-Wire. Unplug battery, push the brake pedal in, reconnect battery. With all accessories/AC off, let it idle for about 10 mins, turn AC on, let idle for another 10. It will let the ECU relearn your idle settings.