1996 Jaguar XJ6 2 Wheel Drive Type Automatic 137,600 miles I was told by the jag dealer that I needed 2 upstream oxygen sensors and this is why my check engine light is on. I looked and the car has 4 two near the bottom of the manifold pipe and two closer to the front. They say it's the upstream one's I need. Which one's are the up stream? Do I have to get the car scanned again after I replace them or does the light go off after I drive it a while?
The upstream are the ones closest to the engine. They are before the cat converter. If you have the codes cleared the light will go right out, or it will take several drive cycles to clear on its own. If you want you don't have to go to jag to have it cleared. Your local auto zone can do it for you for free, or you can purchase a generic obd2 code reader and do it yourself for about 50$.