I have a 2000 silverado it has an intermittent power loss after shifting into gear. it revs just fine in park. I can pump the gas petal and in a couple of seconds its back to normal. No codes flashing
In park the engine revs up normally. it takes a couple of seconds pumping the
gas and it starts running fine again. 1st time it happened I was towing a trailer
up hill. Now the loss of power (engine cuts out) when its been sitting a day or
two and only at start up.