recently installed a jdm d16a into my 91 crx dx with a p28 ecu coverted to obd1. i replaced the timing belt, water pump/tensoiner, spark plugs, plug wires, cap and rotor. it seems to be running a little rich and my gas mileage isnt the best. timing seems to be spot on. also after a little while of driving the engine light comes on and i cant get it to display a code. im thinking that the ecu might be bad. any thoughts?