Code 71 & 73 Issue...

yes, I've searched for weeks and done almost everything I found online that made sense. No luck so far.

car is a bone stock 1996 integra LS w/ RHD conversion. 96 JDM ITR dash harness, 96 USDM LS engine harness. I ran crank angle sensor wires & secondary O2 wires directly to ECU without no codes related to them.

issue: The car throws random misfires on cylinder 1 & 3 only and its intermittent. Seems to happen only when the car is warm. If I reset the ECU, the CEL goes away but returns about 10-15 minutes of driving.

Things I've done so far:

a.) with the CEL on (code 71 and 73) and engine running, I disconnected spark plug wire 1 and it made the car bog and the engine shake. Same results with spark plug wire 3. I can see and hear the spark and feel the clicks as I was removing the wires. (Meaning there is spark)

b.) I've changed all these with OEM parts: Cap, rotor, spark plugs (.45 gap), plug wires, coil, fuel filter, main relay, ECU, Injectors w/ o rings - same results.

c.) I've checked all my vacuum lines for cracks and leaks and found none.

Things that could be suspect...

compression - I have yet to do a compression check, but wouldn't a bad compression make your car idle and run like crap, and the misfire would be constant? My car runs and Idles fine even right after the CEL appears.

Igniter or ICM - but wouldn't this cause a random misfire on any cylinder? my car happens only on 1 & 3

Fuel pump/ fuel pressure guage - cause of misfire could be same scenario as an igniter. right?

Bent valves - dont know how to check that.

My Fuel cut off kill switch... Maybe?

Running Crank angle sensor directly to ECU w/ just plain 18guage wires. I was throwing code 54 wiring it eliminated that code.


HELP!!!!! I am so super frustrated with cel code 71 & 73 I am ready to just drop a new motor... Could there be anything that I have overlooked?


thanks H-T.

 

Well first of all, how did you make a USDM engine harness work with RHD? Did you cut and extend all the wires to connect up on the correct sides of the car at the firewall (opposite the original OEM locations)? If so, it could be a problem with stuff you've cut and extended.

 

I got this set up like this, as far as I can tell only a few sensors were cut and extended. The car is not throwing any other CEL codes but 71 and 73. I thought honda engine sensors are either "ON" or "OFF" meaning the reading of the sensor will not be affected just by lengthening or shortening the wires. As long as the crimps are done right and the cut is moderate. Isn't this how they do wire tucks?

But anywho can anyone one else confirm this that the wire harness might be the problem? thanks