I've noticed the same problem with my 4Runner lately <img src="/forums/images/graemlins/confused.gif" alt="" /> No stored trouble codes and disabling the EGR valve makes no difference. It feels as if there is no ignition advance. Advancing the base timing makes it run better when its acting up but is no real solution. My TPS is properly adjusted and sweeping nicely. I've tried a different knock sensor just in case the ECM was recieving an erronious report of pinging. I even tried my spare ECM. Of course I also confirmed minimal voltage drop on the main power and ground circuits as well as many of the sensor signal circuits. Under what other actual or percieved conditions will the ECM inhibit ignition advance? <img src="/forums/images/graemlins/confused.gif" alt="" />