I jhave a 1999 ford taurus and the check engine light is on and the only code is for the oxygen sensor and i already replaced the sensor and the problem has gotten worse. The wires the oxygen sensor plugs into (engine wiring harness) are chewed up but the new wires are $1,000 any sugestions?

bank 1 sensor 1 lean code. Check vacuum lines first. Could be egr leak also. Most vacuum lines run on the back side of the engine on these. Most common fail is the PCV 90 degree elbow. On the passenger side.

Go to an Autozone, Oreily, or Advance auto parts store. They will scan you car for free and can reveal the Code and possible fix.

Possibly the air sensors went out of balance when there was no fresh air. Sounds like sensors read the engine as "Lean" due to lack of Oxygen and set engine to a rich setting.

As for your codes p1131 and 1151: Ford - Lack Of Heated Oxygen Sensor Bank 1 Sensor 1 Switches - Sensor Indicates Lean


Last week I had the very same catalyst, evap and ECG codes come up on my 1999 Mercury Mystique which is like a Ford Taurus. A friend was able to find a hole or leak in the hose connected, replaced it and it runs fine. I havent run it a full and straight 50 miles yet to clear the check engine light but that repair alone changed the entire way the car was poorly driving. Im sure that hasnt fixed all the probs but thats a good starting point.

P0442 FORD - Evaporative Emission System Leak Detected Small Leak

Possible causes- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
P0136 - O2 Sensor Circuit Malfunction Bank 1 Sensor 2
Possible causes- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Faulty Rear Heated Oxygen Sensor Bank 1
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks

P0141 FORD - O2 Heater Circuit Bank 1 Sensor 2

Possible causes- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit fuse
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit poor electrical connection
- Faulty Engine Control Module (ECM)

P1131 Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Lean...

P1132 Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Rich...

If it was an Oxygen sensor it would most likely cause the CHECK ENGINE LIGHT to come on.
I would check the spatk plugs and condition of the plug wires first.

This code is the circuit malfunction for the oxygen sensor bank 1 sensor 2. This means that the engine computer is not seeing the sensor. It may need an new sensor, have a wire between the sensor and the computer that has shorted out, or just be unplugged. Here is a link to a trouble code dictionary.

http://www.troublecodes.net/OBD2/Pcodes.shtml

oxygen sensor failure
P0171 System too Lean (Bank 1) - Read Our Article On Oxygen Sensor Codes For Help With This Generic Check Engine Light Code
P0174 System too Lean (Bank 2) - Read Our Article On Oxygen Sensor Codes For Help With This Generic Check Engine Light Code
hope this is a bit of a push in the right direction ...

P174 means Oxygen sensor was slow in switching Single, Right or Rear HO2S - Fuel control

P171 means Oxygen sensor not switching - system was at adaptive limits - Single, Right or Rear HO2S - Fuel control

Visit http://www.troublecodes.net/Ford/
for a comprehensive code listing for your car.

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Usually there is a p in front of the numbers like p0136. If that's what it is, it's the oxygen sensor. The one on bank #1, #2 sensor, the one down by the catalytic converter under the vehicle. replacing it should solve the problem.