AKondomodelinasquaretight-bondinglatticeofconductionelectronsisconsidered.TheKondointeractiontakesad-wave.Usingmean-fieldtheoryandnumericalsimulations,itisfoundthatthereisapseudo-gapfortheimpuritydensityofstatesattheFermilevel.Numericalresultsalsoshowthattheexponentsofthelowtemperaturethermodynamicquantitiesarenon-universalbutdependentontheinteraction.