i have a 2000 chevy blazer its got the 4.6 v6 178xxx mileage,the concern i have is that it idles hard but when your driving its fine . It had bad engine mounts and those were replaced , did a full tune up plugs cables filters,oil change,distibutor cap.Fuel economy is also very bad.It has no cat converter ?could that have something to do with it ? have one i bought new at advance autoparts for $97 just havent gotten around to putting it in.I think it could be a sensor?

 

Is the check engine light on? What are the codes?

Have you checked over the vacuum lines for leaks? Cleaned the MAF sensor, EGR valve, and/or throttle body (including IAC valve)? <-- much of that is explained in other threads so search up.

 

yes the check engine light is on , i checked it and all i got was "engine misfire" checked spark pluug wiring and its correct.where is the maf sensor located ? what is used to clean it?