Hello i've posted this over in 92-2000 with little help hopefully someone here has an idea what might be wrong thanks.

i have a 97 stock hatch with a d16y7 a couple weeks ago cel code 65 came on while driving for no reason the secondary o2 is good. the car had a header/cat which i swapped with a buddy for the stock manifold/cat he had no cel and once i put the exhaust on and started my car cel came on, code 65 again. now this is with his o2 sensor and cat which worked perfect hours before this and my old sensor now in his car with the header/cat works fine with no cel.

i have reset the ecu a few times, and within 15 seconds of the car starting the cel comes on for code 65. i have no exhaust leak. i reset the ecu unplugged the o2 and same thing within 15 seconds the cel came on for code 65. i got the following ecu pin diagram. http://www.phearable.net/tech/wiring...schematics.gif

went out today with the pin diagram and checked for continuity between the o2 plug (nearest to the sensor) and the ecu i found that i had 0 ohms of resistance for

connector A pin 5 and O2 plug
connector D pin 13 and O2 plug
connector D pin 15 and O2 plug
and the last wire (black with yellow stripe) went to ground, i could not find it on the diagram so i assumed that it was suppose to go to ground. i also grounded my volt meter and checked for voltage on the connector D pin 14 (SHO2S-secondary heated O2 sensor) and it was around 0.4-0.6. i thought maybe the sensor was getting old and was operating slow so i replaced it with a brand new bosch reset the check engine light, started the car and same thing within 15 seconds cel code 65 came back on.

hopefully someone has an idea because at this point i'm stumped. I'm going to try another ecu tomorrow. the car is still only throwing code 65