I recently bought a 91 Corsica with the 3.1 V6 engine. It'* not running very well. Fault codes 43 and 45. I'm thinking maybe the knock sensor. I understand it'* located behind the engine, seems difficult to get to. I want to disconnect or disable the knock sensor somehow so to see if there will be any change in how the car runs. If it starts to run more stable then maybe it really is the knock sensor that needs replacement.

The car has 55 000 miles and is otherwise in excellent condition. Bought it from a 79-year old man who bought it new in 1991. Today he'* stuck with a oxygen tube so he felt he couldn't use the car anymore.

PS The Power steering feels really heavy. It was low on oil, I filled it up to the mark but there'* no change. PS pump bad?

Try a complete tuneup first. That knock sensor is there to protect your engine from pre-detonation and destruction.

diagnosis for the code 43 knock sensor performance is pretty cut and dry. Check your connections a the sensor. Check the resistance of the sensor with a voltmeter. Terminal to housing should be around 3300-4500 ohms. Pcms are also known to fail on these cars, internal circuit boards failures are common.

Code 45 is for high voltage O2 sensor. 50 second duration or more. I'd deal with that before I sank the money into a "complete tuneup". Many things can trip a 43 fault code with a single instance.

Did this car sit for a long time? Are there any noises when turning hard or just the heavy steering feel?

you should be able to reach the back of the motor once you jack up either side and take the wheel off, you may have to take off a splash shield. More than likely the connector may be loose, if not remove squirt both halves with electrical contact cleaner and reinstall. If you actually want to delete the knock sensor go to HP Tuners, their VCM suite you can change all kinds of parameters in the PCM OS , delete the EGR to while your at it LOL. Just make sure to put it back in before your next emissions inspection

im with mike, 43 is esc and 45 is rich exhaust, 45 could be caused by the poor running of the spark system, i would start with plugs and wires if they havent been done and then go from there. its always good troubleshooting procedure to do one thing at a time with multiple codes and then re-baseline because things affect others that you woulndt think about

hes not going to do this on a 91. and its generally not a good idea anyway, both help with fuel economy

HPTuners will not touch anything below 1997.

I know , I was laughing in my mind when I did it, sorry

probably OBD1