I recently had intake manifold gaskets replaced in my 98 gmc sierra 4x4 pickup 5.7 . The day I drove it home from the shop it ran fine, even day after but the next day I noticed it seem to idle a little rough and even at normal driving, sometimes seems worse than others. No service engine light has yet to come on. Could there be vacuum leak, trash in intake or bad wires and plugs. Plugs, wires, rotor button and distributor cap are only year and half old, any ideas?
Talk to the people who did it my guess would be leak/ gunk left behind… could be coinsidence but with cars i rarely assume that.