Modern engines contain dozens of sensors and controllers, most of which behave well over the life of the vehicle and never have to be replaced. But every once in a while there’s a bad apple that can ...

Question: I have a 1999 Chevrolet Silverado S10 and, lately, the engine has been surging while at an idle. I was told this could be a “dirty ETV valve.” Does that sound right? What else might be the ...