I've got a misfire, and I've been getting a check engine light sometimes. Sometimes the check engine light will come on all day and stay on. sometimes it will not come on at all all day. Sometimes when it is on, if I slam the gas, it turns off.

As far as the misfire goes, when the check engine light turns off, the engine idles differently. It doesn't sound as choppy whent the light is on. Then if I'm driving I will get the misfire and a split second later the check engine light will come on. I'm stumped.

I got code 43 for knock sensor or circuit and lean codes for both cylinder banks. Would any one of those three things be linked to an intermittent misfire?

 

Lean running or bad O2 reading might be causing you some trouble, but OBD-I has no misfire detection. There is info on how to test the knock sensor and circuit on my Tech Page.

 

Would a bad o2 reading cause an intermittent misfire?

I am not able to currently test the knock sensor circuit as it says on your web page. I do not have a meter.

 

Hey Shoebox, I'm going to replace my knock sensor... whats on the other side of the sensor in the block? Any fluids?

 

Yep, coolant! The knock sensor doubles as the block drain for that side.

 

damn! is it possible to change without draining the coolant?

 

Nope

Z

 

Since that is the lowest part of the cooling system, I don't see how. Have everything ready and swap it real fast. It might be a little messy, but you might not lose much. Wear eye protection.

 

Yep, I've done it before. If you do it quick enough, the loss is minimal. Make sure the engine is cold.

 

It's not that tricky because I did it too and only lost about an ounce of
coolant. Just raise the car high enough so you have room to work with
both hands. Take out the KS with one and quickly plug the hole with a
finger on the other hand. If you are right handed plug the hole with your
left. Then thread in the new KS. As Ion said, cool engine is a must. Also,
don't take off the radiator cap. I think there may be a tiny amount of
vacuum in the system which helps hold the coolant in.

 

awesome, thanks guys!

 

If you have to replace the knock sensor or the wiring, is it better to just go ahead and replace both?

 

Test the knock sensor with an volt/ohm meter.

http://shbox.com/1/4th_gen_tech2.html#knock_sensor

If you see damage to the wire, I'd just splice in new wire. If the connector is damaged, you can get a new connector and slpice it in also.

ZMAN