i have a 95 blazer 4.3 car is running rich/alot of air it doesn't back fire or nothing just spending a lot of gas any ideas? i was thinking the map sensor but i would like help with problem

 

Any DTC's? If it's running rich it has to much gas and not enough air and if it's got to much air and not enough gas it's running lean. Both are bad and should be addressed ASAP whichever your situation may be. When you say it's using a lot of gas please define. For example what's your mpg's and have they recently taken a dive? Has this always been a problem or is it new? These things aren't know for great gas mileage.