1996 accord 2.2L, 5 speed-trouble code?
 

Got a code #66 from jumping my ECU following a check engine light. Comes back on immediately after I try to clear codes. I see a code 65 and a code 67 in the book. Should I get OBDII read for better understanding. Thanks

code 65 is secondary oxygen sensor heater

my trouble code list doesnt have 66 either

67 is Catalyst system Efficiency Below Threshold
malfunctioning or defective catalyst system

Id get an OBD II reading to verify the code numbers you got.

If you live near an autozone you can get one of the code readers if you put down a deposit of about 162 depending on tax you get it all back tho.

If your not buy an autozone just take it w\e

Just make sure you get the exact code including any letters before the numbers. If theres a P or U there will be 4 digits after it. The code will be 1-2 numbers if there is no letter prefix.

And unless the place has Honda specific reader the code description from the reading device wont be the actual problem.