Hello, This occurs less than 5% of the time, and it has done so off and on the three years we have owned this 2001:

The Blazer will start and will idle rough, will not idle without the throttle pressed, you have to do some two feet manouvering (one on brake, one on gas) at stop lights to keep it running. There is no SES light on, I assume the ECM has somehow lost power and the car is in limp mode. MPG drops as well. Sometimes you can turn it off and back on and it will run fine then. I have also noticed that any stored codes are gone after the above occurs.

I recall reading in the past that there is a ground wire I should investigate. I'm also tempted to replace the ECM.

Any one else with this experience?

Thanks in advance!

 

Sounds similar to the problem I am having.
https://blazerforum.com/forum/2nd-ge...misfire-69883/

 

In our trucks {or most vehicles} it is much more likely to be wiring than a module bad. Not saying it cant happen, but check those power and grounds first. Start with 5v and ref gnd on the sensors.
Also the grounds back of the engine. Sometimes will cause codes but not always.