few things to know

got a 88 honda civic hb....and the check engine light comes on after its been drivin for a bit...actually it depends on how hard im runnin it....anyway to figure out what is wrong with it?

and another thing is....( kinda hard to explain so bare wit me).....when im accelerating there is a slight knocking noise...its not anything loud you can just barely hear it over the motor...not sure what could be causin it...cuz its got plenty of oil....my uncle said it could be that the timing is off a notch....could this be causin it at all?

on the passenger side, near where the feet goes, peel back the carpet and theres the ecu, in the middle, theres a clear circle, when its visible, turn the key to just before the engine starts and everything lights up. then look to the ecu hole, count the blinks after the first blink. it should be between 1 and 20. look out for the patterns though, they repeat after 1 or 2 seconds.

then go to google and search for 88-91 civic error codes and it gives a list of codes and problems.

On the passenger side of the car, pull back the carpet and remove the metal cover for the ECU. (right where the passengers feet go)

Turn the key in the "on" position (don't need to start it) and count how many times the light in the middle of the ECU is flashing.

That will help to start. :)

hmmm....it just keeps flashing....do i need to keep couting how many times it flashes until it stops?

it flashes 2 times...stays off for a few sec. and then comes back on and keeps flashing at the same interval...the code for it says that its the oxygen sensor 'b'.....just wondering if this was the right one...and where its located and how can it be replaced?

Does your car have two oxygen sensors? If so, its probably the 2nd one. :)

k then.....but where is it at?

its bellow ur car in the piping that goes from the manifold and the end of the exhaust pipe.ull se a sensor like about the sise of 4 or five inches and a whire atached to it. that is the o2 sensor