Dead oxygen sensor.

[amys4x4explorer]

Had a loose tail pipe so had it welded on, soon after that my check engine light came on, the computer that was hooked up to my ford said it was a bad oxygen sensor. What will happen if I don't replace it? How many are there on a 98 ford explorer.

 

[01dbsc2]

well i can tell you there are four 02 sensors if you have the V8. Now i just replaced all four and it wasn't exactly fun. And all that will happen is you will fail inspections (if you have them) and you will see your gas mileage deteriorate. Also did it say which one was bad? bank 1 sensor 1 anything like that?

 

[aldive]

What was the actual OBD II trouble code?

 

[amys4x4explorer]

P0101

 

[2000StreetRod]

MAF not O2 sensor

P0101 Mass or Volume Air Flow Circuit Range/Performance Problem

The code has to do with the measurement of air flow thru the MAF sensor and nothing to do with the O2 sensor. Are you sure that you posted the correct code?