hi i have a 2001 escort with a 2.0 sohc. the problem im having is that both the up and down stream o2 sensors shows 0.00V with my scanner viewing the live data. also the long term fuel % is -100.this tells me that the car is running very lean.It doesnt set a code for this problem. I was wondering if anybody else has had this kind of trouble and what it may take to fix it. :banghead:
thanks in advance

I wouldn't worry about it running lean as long as you don't have any signs of detonation, running lean will help fuel mileage. If it was running too lean the ECU would set a code.

i understand that running lean should help the fuel mileage but my car is only getting about 25-26mpg.my 95 escort had a 1.9 sohc which is pretty much the same setup got 33mpg. Do u have any idea what causes the problem on the 01 model like i described?

How many miles are on the O2 sensors? I don't trust them past 100,000 miles.

Having said that, excatly where are you getting this 0V reading from? Are you running the car, with it warmed up and reading the voltage from the wiring harness with it unplugged, or something?

i have a autoxray 5000 scantool. that shows me live data view of what all the sensors are doing and on o2 sensors it cycles above and below 450 milivolts depending on how rich or lean the engine is the running.In my particular case the voltage reads o.oov no matter if the engine is hot or cold also the fuel trim is -100%. (the sensors are new)same thing shows up with the original sensors,but it does not throw a trouble code.

I don't think you have a problem with the O2 sensors - I think it's more likely to be a communication problem between the scan tool and the PCM.

Looking at the wiring diagram, the O2 sensors each have separate 12V feeds to the heating element, with separate ground returns into the PCM, and separate 12V feeds into the high end of the actual sensors, with separate outputs into the PCM - the latter is the point at which your scan tool is reporting 0V on both sensors.

2001 Escort O2 sensors - wiring diagram (http://i180.photobucket.com/albums/x64/Selectron/Escort/2001-Escort-O2-sensors.png)

I can't see any way in which the wiring or connectors would be likely to fail and cause the PCM to read 0V from both sensors at the same time, so if you can get a multimeter into circuit then I'm sure you''ll find the output voltage from each sensor is indeed present.

If access to the connectors is reasonable then you can measure the output voltage by connecting the meter's black probe to ground, and the red probe to the grey/green wire on one sensor, and then for the other sensor it's black probe to ground again, and red probe to the grey wire (multimeter on the DC voltage range, leave the connectors plugged in, and probe into the back of the connector).

If access is poor then I wouldn't even attempt to measure the voltages, because chances are they're just fine, and it will turn out to be a communications problem.

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So, I was just about to post that some sixteen hours ago when my ISP went offline and it's been unavailable ever since, so I'm on a pay-per-minute dial-up connection at the moment which I hate using because I end up with big phone bills so I won't be online much for a while, if at all.

Do a Google search including the terms escort both o2 sensors 0v - I had a quick look last night before my ISP failed, and I saw several reports of the same issue (including the -100% fuel trim) on various vehicles, at least one of which was an Escort. That particular instance was apparently resolved by replacing the PCM, but don't do that without first trying a PCM reset because perhaps that's all that would have been required. To reset the PCM, just disconnect the battery negative cable for a minimum five minutes. After you reconnect the power, you may experience some driveability issues for a while as the PCM relearns its optimum settings.

Don't do anything too hasty without researching the issue on Google first though, because there is some information out there, and I'll rejoin the thread when my ISP eventually comes back online.

thanks for the info. ill do some more test and see whats going on.But just because the sensors are producing voltage at the connector doesnt mean the ecm is receiving the signal am i right.Also i forgot to mention that i get same results with the o2's unplugged.

just did googled ur suggestion seems everybody who is having this problem is getting code p1131.thats is what throwing me off im not getting a code. thanks again