Clogged catalytic converter? O2 Sensor?

[stodge]

I'm having a problem with my 2000 Taurus SE. I'm getting poor fuel economy (I know it has poor economy anyway, but it's much worse than it should be). I reckon it's 25% less efficient than it should be.

Also, when the engine is anywhere from just startin to warm up to normal running temperature, it hesitates when cruising and accelerating. When I accelerate it seems to choke, so I have to use more gas to get the speed I want. The acceleration isn't smooth. The worst symptom is that when I'm cruising around 50km/h to 60km/h and I accelerate (any level of acceleration), the revs actually drop slightly, the engine does accelerate a little bit, but it won't accelerate normally until I floor it and force it to change down a gear.

When the engine is cold, it runs very smoothly. Do these symptoms sound familiar to anyone? I took it into a local dealer to look at. I asked them to check the cat, but they said their was nothing wrong.

Thanks

[Bodin]

My sister had a 2002 Focus and it did the same thing. She lived in Vancouver, B.C. when she bought the car but when she moved to Penticton, where it is very hot in the summers, she experienced abnormal acceleration. I remember that she took it to Ford a number of times and I think it ended up being the 02 sensor. It might also have something to do with the fuel pump/lines... I am really not too sure... I'll talk to her and get back to you.

Anyways she ended up trading it in for a Dodge because she had a hard time dealing with Ford.

[stodge]

Thanks. Is it possible to visibly diagnose a broken o2 sensor? E.g. if I could get the car up on a ramp?

[articsteve]

The sensor can be measured for resistance.  You need the appropriate chart.  I doubt it is an O2 sensor though.  Are there 2 in that car?  I would think a bad sensor would throw out a code.

Somewhere on google will be a chart and instructions on how to measure a O2 sensor.

It's something else.  I had a Town Car with a 302 and it would stumble like mad on a hot restart.  I pissed around with that problem for years.

All I can say is that it's a Ford and they make some really bad crap.  I warned you not to buy that car.

Cats don't often clog and if they do you will have a real drop in power up hills.  Take it to Ford on your day off after you get the motor nice and hot and get it read by their code reader.  None Ford code readers will not be nearly as good.

Other than that, if you got the guts, torch it.

[stodge]

I do get a power drop up hills. It's already been in to Ford, and they said there were no codes, nor was there anything wrong with the cat. Of course, being the expert mechanic I don't believe them! ;)