Average diagnosis time your Jeep should require is 2 hours. At the average rate of $60.00 per hour for smog check failure diagnosis, finding out the reason your Jeep failed for high NO should cost around $120.00. Now depending on which component(s) end up being defective, the total cost of this smog check repair will vary.
The most expensive emission component will be the CAT. Aftermarket CAT will cost approximately $250.00. Please note State law requires the Catalytic Converter be replaced ONLY after all other emissions systems have been diagnosed, and if needed, repaired.
The most inexpensive part would be the oxygen sensor. We found aftermarket oxygen sensors for your 1989 Jeep for under $60.00.
Bottom line, the cost of getting your Jeep to pass the smog check will be very dependent on the reason for its failure. We should mention, in California, the average smog check diagnosis and repair costs around $500.00.
