Hey all, I have a 2004 lj unlimited. I am having horrible fuel mileage... I changed the water temp sensor did not change a thing so the next is oxygen sensor or vaccum leak. For the sensor which one would be the problem.
The upstream O2 sensors above the two small pre-catalytic converters. If you replace them make sure to avoid Bosch and use only either NTK or NGK O2 sensors.
The upstream O2 sensors above the two small pre-catalytic converters. If you replace them make sure to avoid Bosch and use only either NTK or NGK O2 sensors.
The upstream O2 sensors above the two small pre-catalytic converters. If you replace them make sure to avoid Bosch and use only either NTK or NGK O2 sensors.
Bad O2 sensors rarely throw a code, the computer isn't usually smart enough to know when one or both are lying. And without a specific code pointing at a specific O2 sensor I'd replace them both if you suspect they're the cause of the poor mpg. And one or both are certainly more than capable of doing just that.