oxygen sensore / fuel filter questions

I have 125000 miles on my 98 XJ

I never replaced the o2 sensor...my mileage is not what it used to be and did all the other general tune up stuff

Should I replace the o2 sensor

Is it a simple replacement (like changing an oil filter) or do I need to do something else?

I never replaced the fuel filter and the Hayes book says it is in the gas tank....I now want to replace it....do I have to remove the whole tank (drop the tank down to get at it) or is there an easier way to get at the filter?

I dont have a 98 but but on my 92 and my 89 the o2 sensor just uncrews then unplugs, very simple. I am not sure about the fuel filter but you say you have the Haynes, doesnt it go into changing it in there, I know there is alot of stuff left out of that book so maybe it doesnt go into depth on it.

Chris

thanks....yeah the Hayes book can be pretty light on detail....

but with the o2...do I need to have anything in car's computer reset or do I just set it and forget it?

Just unscrew and install. It's usually easier when the exhaust is hot.

And first unplug the sensor. Makes it much easier. And when you put the new one in: Do not touch the sensor tip. Don't get any dirt or grease at it. It will ruin it. Or at least it will shorten it's life cycle.