I did a b16a swap in my 90 CRX DX it runs good, except for the point that it is very rich. So rich that you can see smell it and there is a coating of black **** on the back of my car that is unburned fuel. I took it to the mechanic and he changed the O2 sensors, and the injectors. Then the timing belt got changed and it is still running real rich. I am running a chipped PR3 and I also have a PW0 ecu they both do the same thing. Does anybody have any ideas of what it could be. I have brought it to multiple people and nobody can figure this out. I need somebody that is smart and I know that theres somebody out there that has had the same problem and knows how to get rid of it. So come on and help me.

 

I'd try advancing the timing on the dizzy. Chipped ecu's usually do run rich on stock motors. Do you have an aftermarket fuel pump? Cause if you do and you don't have a regulator that could be it also. Someone on here will definately help cause they've had this problem a lot.

 

But it does it on both ecu's. Thats whats confusing me. Other than a chipped ecu the engine is stock. No upgraded fuel pump, no cams, nothing else. I only have a apexi world sport exhaust. I also have a high flow cat... would that cause this problem?

 

Is the aftermarket ECU tuned for that engine?

 

Yes... But nobody understands I have a virgin PW0 ecu that does the same thing. Its not the ecu