Review on NGK Oxygen Sensor 23023 by Micael Rau

My 363,000 miles 1992 Jeep Wrangler 4.0L could not handle the high NOX at 15 and 25 mph (1028 and 1800). Catalyst replaced and tuned, fitted a two year old Denso oxygen sensor, still counting cylinders fast, decarburized cylinders, used 91 octane and guaranteed to let gas additive through. Tested again and still failed the High NOX test, but the readings have gone down (828 and 1030). After reading a review about this sensor being a factory replacement and other brand oxygen sensors not working properly I decided to install this NGK sensor and crossed my fingers. Took my jeep to another workshop who warmed up the engine and catalytic converter properly and everything ran brilliantly. NOX was 308 at 15 mph and 138 at 25 mph. I am convinced that using the original oxygen sensor made a difference.