1995 Jeep Cherokee emissions controls

Engine Performance problem
1995 Jeep Cherokee 6 cyl Four Wheel Drive Manual

Lets try this again, nitrous oxides are at double plus the allowable for this vehicle. All other parameters are well within spec. At half or less of allowable. This generally leads me to the E.G.R. Loop, either the ports are plugged with carbon, or the E.G.R. Valve is not functioning. To the best of my visual, there does not seem to be an E.G.R. At all on this vehicle. I have pulled the throttle body and looked in the intake for any signs of coking or carbon from an E.G.R., But see no signs of such. Is there something else that would raise the NOX levels without affecting driveability? F.Y.I. I am A.S.E. Cert. PARTS not Tech. This is making me nutty. Thanks for your consideration.