I got a DOHC ZC motor in my 90 hatch with a zc ecu. i took it to pass emissions last week, everything passed but my CO% was WAY too high. which i guess my fuel is too rich?. i need to be at 1.00 and i was at 3.83. i was wondering if anybody knows an easy trick to do to get this passed emissions. i was thinking a us si ecu, or maybe a apexi vafc? any help would be rad!! thanks

 

Yeah an si ecu should do it..It will run it pretty lean..

I dont get how it would be running to rich though ,if its the proper ecu for that motor..?

 

Well CO is incomplete burn of fuel. It could be from a plugged air filter to bad plugs.

I would guess your HC's are close to max level for passing also.
Could it be old gas?
What octane did you run the test with? try 87 it burns easier.

Will you let us know what you do, and if you pass.

 

i got a K&N filter for intake, but i haven't changed my plugs for a while and i think i was on regular gas. ill try tweeking a few things and try the si ecu. ill keep you posted