'97 3.8l - p0133

[fdunford]

Getting a P0133 slow response all of a sudden. Both O2 sensors were changed about 60,000 miles ago. Comments?

Where is the p0133 sensor located on 1997 ford windstar (please don't say upstream/downstream - say radiator side or muffler side or someting that makes sense )?

Thanks!

[wiswind]

This is Bank 1 upstream sensor.
Bank 1 is the rear bank of cylinders.....closest to the passenger compartment.
The sensor is located in the pipe comming from the rear exhaust manifold.
On my '96, I cannot readily see it from under the vehicle.....without a flashlight.....
It is on the part of the pipe that goes up to the motor.
It is easy to get to from under the vehicle.......I drive the front end up onto a set of ramps.

A oxygen sensor should last much longer than 60Kmiles.....
I like to change the upstream oxygen sensors as a pair in order to have a matched set of switching charactoristics.
You can pick up Genuine Motorcraft branded oxygen sensors at Rockauto, if you want to stay with OEM.....for the price difference....I decided to stay with OEM.....although I saw no change when I replaced mine at someplace around 163K miles or so.

[fdunford]

wiswind,

Thanks for your reply. If I understand you, the p0133 is the exhaust side sensor - great. I will take a look at this and look for anything unusual.

I also thought that the OEM sensor I put on 60K ago should still be good. Do you think a battery on the hairy edge of failure could contribute to the p0133 (my battery failed yesterday - will change tomorrow)?

[wiswind]

A weak battery can cause all kinds of strange error messages.....
I would see if this code comes back after you replace the battery with a new one.
Worth a try to save some $$$ and replace a part that you KNOW is bad.

[fdunford]

No luck. A new battery and 3 O2 sensors later, the code is back. Any ideas, anyone, wiswind, Bueller?

[serge_saati]

Ford's computer is very sensitive. It throws codes if sensors heats or cool a bit more slowly. The long as the engine operate correctly with good performance, you should not worry.

You want to repair the problem to decrease fuel consumption or just to get rid of this orange light in the dash?

If sensors don't last, maybe the car backfires a bit.

[wiswind]

Other things that I wonder.......Which code is listed first?.....P0171 or P0133?.
A long shot would be some cleaner for the fuel injectors......Berryman's B-12 Chemtool.
Also give your ignition system a checking over.....coil pack, plugs, plug wires.
Look for vaccum leaks.......vaccum lines, PCV line, Brake booster line, etc.
Are BOTH IMRC actuators working properly?.......make note of the position of the IMRC shafts with the engine NOT running......then start the engine and check again.
They should be OPEN with the engine not running, and CLOSED with the engine running.