kneadraggr
04-05-2008, 11:27 PM
This is by NO means meant to be a comprehensive trouble-shooting guide, just what I did to fix this problem on my Cougar. Hope it helps somebody. My Cougar is a 1999 4cyl, 5 speed.
Symptoms: Car was low on power, and cut out (jerked) between 2500, and 3500 rpm at partial throttle. My Actron code reader showed P0135, and P0141 errors. They both point to a problem with one of the O2 Sensors. Problem could either be the sensor, a connection to the sensor, or a fuse.
First I went for the easy kill, and replaced the pre-cat HO2S sensor. I went with the pre-cat, because this is the one the system uses for fuel calculation. The post-cat is used to monitor the function of the cat. That did not fix it.
I found and replaced a blown fuse in the under hood fuse box. According to my Chilton manual this is fuse 13, it is the 3rd fuse of 4, (2nd 20 amp, between the 3, and 15 amp fuses counting from the air box toward the fender). Still did not fix it.
Next I found that the Negative terminal was loose on the battery. After removing, and cleaning both Positive, and Negative battery terminals the problem was fixed.
Now, the fuse was very bad, and something caused it to blow, and it could have been a short in the O2 sensor (or not?), and the battery terminals were corroding, and loose. However the final step of fixing the terminals may have only helped by removing power from the on board system, and causing a reset after fixing one of the other problems. Also I just purchased this car, and it had a lot of questionable wiring for a stereo, that I have also removed. This could have been a factor, but should not have been since it was either wired to the battery directly, or on a different circuit. Either way I do not know much about the history of the car, or when this problem started.
Good luck
Symptoms: Car was low on power, and cut out (jerked) between 2500, and 3500 rpm at partial throttle. My Actron code reader showed P0135, and P0141 errors. They both point to a problem with one of the O2 Sensors. Problem could either be the sensor, a connection to the sensor, or a fuse.
First I went for the easy kill, and replaced the pre-cat HO2S sensor. I went with the pre-cat, because this is the one the system uses for fuel calculation. The post-cat is used to monitor the function of the cat. That did not fix it.
I found and replaced a blown fuse in the under hood fuse box. According to my Chilton manual this is fuse 13, it is the 3rd fuse of 4, (2nd 20 amp, between the 3, and 15 amp fuses counting from the air box toward the fender). Still did not fix it.
Next I found that the Negative terminal was loose on the battery. After removing, and cleaning both Positive, and Negative battery terminals the problem was fixed.
Now, the fuse was very bad, and something caused it to blow, and it could have been a short in the O2 sensor (or not?), and the battery terminals were corroding, and loose. However the final step of fixing the terminals may have only helped by removing power from the on board system, and causing a reset after fixing one of the other problems. Also I just purchased this car, and it had a lot of questionable wiring for a stereo, that I have also removed. This could have been a factor, but should not have been since it was either wired to the battery directly, or on a different circuit. Either way I do not know much about the history of the car, or when this problem started.
Good luck