my 90 da w/b16a is throwing a code 4 and 23 what is it and want needs to be done to fixed it.

 

Code 4 is crank angle. Not sure about code 23.

 

code 23 = knock sensor

how is the motor running? anything else we should know about the car?

 

the car i completely stock the problem is my engine light come on and sometime my rpm start jumping all over the place ho do i correct these problem. someone said the time he got a 4 he just replace his distributor.