Oxy Sensor/CheckEngineLight/Major gas Problem

I do not have autozone codes handy, the machine is down at the shop for a week or two, but this problem is driving me crazy and costing me a nice amount of money.

98 Contour Sport
99,927 Miles

My check engine light is ON.
I assume it is the Oxy Sensor, though, thats just an assumption.
My gas mileage has gone WAY downhill. I used to use half a tank a week.
Now it is half a tank every 2 days, if im lucky.
I also used to use 89octane, but now with prices so high and my need to refuel so often I use 87.
I was thinking about taking it into the shop, since it probably needs more work (tune up, so on and so forth).

Any ideas?

I will actually drive out to a different autozone tonight, and get the codes.

sounds like the symptons of a rich 02 sensor to me. Btw, 87 octane will work perfectly fine in your car.

Yeah, I got the code

P0420 - The PCM has detected that the catalyst system efficency for bank 1 is below threshold for the current engine operating conditions. (Bank 1 indenifies the location of cylinder #1, while bank 2 indentifies the cylinders on the opposite bank)

So I bought the OS sensor for before the catilytic converter.

Will be putting it in shortly, and hopefully that will fix my problem.

Thanks for your help

Yeah, I got the code

P0420 - The PCM has detected that the catalyst system efficency for bank 1 is below threshold for the current engine operating conditions. (Bank 1 indenifies the location of cylinder #1, while bank 2 indentifies the cylinders on the opposite bank)

So I bought the OS sensor for before the catilytic converter.

Will be putting it in shortly, and hopefully that will fix my problem.

Thanks for your help
:banghead: did the os sensor work I have a 95 with the same gas milage and hard starting frist thing in the morning

The forum is more helpfull when you write back, letting everyone know if it fixed the problem.

holy old thread batman!

btw, if you want a helpful forum, contour.org is the only contour forum, period. This one pretty much sucks. :disappoin

you should fix the link in your sig, it goes to the old forums.

you should fix the link in your sig, it goes to the old forums.

done! :wink: