Hi, I have a 98 civic, with an H22a4 swap did myself. Has wireworx swap harness and P28 ecu with hondata S300 v3 done by hamotorsports. Got car running and throwing code 9, so I ordered new distributor and still getting code. Set timing at 16 degrees and double checked that timing belt has not slipped. Car runs horrible and driving it done the road it bucks bad. But when go full throttle the car pulls fine but part throttle or idle it runs rough and rich.

 

Code 9 can also be caused by a bad CYP sensor wire or bad ECU.

Ohm test the CYP sensor from the two pins of the ECU connector. Post reading.

 

Tested sensor with meter 480 ohms.

 

From ECU connector?

 

What @muellersfan said. Unplug the ECU (disconnect the battery first) and measure the resistance of the three distributor sensor circuits from the ECU plug. This test goes through the ECU adapter, the harness wiring, the plugs under the hood, and as a bonus, the distributor itself, all in one shot. Also test those sensor wires for resistance to ground, it should be open circuit.

 

Yes I did the test as specified all came back good no shorts in the wiring either. But I also did a compression test and it’s not looking good. #1- 180 #2- 70 #3 190 #4 180. This would cause a miss from what I’ve found in research. But would it cause this code?

 

Miss... YES. Code... Nope.

 

So is the code even worth worrying about at this point?

 

I just chased this code for hours on a friend of mine's track car. Ultimately, it would be nice if you could get the MIL to turn off... but if the engine performs normally and doesn't exhibit any undesirable symptoms such as the lack of VTEC or short revving... I would say run it. Oh, and check your codes often to make sure something else hasn't created a problem.

 

VERY Low compression in cyl 3 --> definitely fix this problem there FIRST. Then go from there.