blackcivic11

alright so i have a 97 honda civic with a d16y7 (OBD2) obviously and its throwing three codes

i shorted the ECU to get them and it came up as 71, 72 and 65

i know the first 2 (71 and 72) are mis fires in cylinder 1 and 2------ What could be the problem that is causing this?

and the 65 is "Secondary HO2S Heater Circuit Fault (Sensor 2)" does that just mean i have a faulty secondary O2 sensor on the header?

i appreciate the answer if you can give me them asap

thanks guys im counting on you!!!!

Pothole987

secondary 02 sensor heater. you can take the o2 out and clean it to see if it helps, or your going to need to get another one.
Misfires could be oil in the spark plug tubes shorting the wires out. or plug wires are bad.

blackcivic11

thanks man can anyone confirm? or add more info maybe on the cause of misfire?

Unit44justin

Start out with the potentially easy stuff as stated try replacing your plugs and wires and try cleaning the O2 sensor for the o2 sensor code

*Edit* I think the secondary O2 sensor is the one after the cat and the one on the exhaust manifold is the primary someone correct me if I am wrong

Pothole987

primary is closest to head, just for reference.
secondary IS the one after the cat.