Getting the P1518. Clip is good, and the cable actuates when I start it up and at 5-6k RPM. Sluggish low end & terrible MPG. Have started to notice at a long time idling the RPM's will dive for a split sec then jump to around 2-3k, then slowly come down. Tonight I saw the cable actuate when this happens. Just double checking before I order the IMRC. My best conclusion from all of your folks great info here, is that my IMRC is spazzing out. You guys agree?