a guy from my work bought a 93 civic with a 97 b18b swap. he said the idle was surging and it had a cel, so i checked to see what codes he was pulling. it was 12 (egr) and 41(primary 02).i have never owned a obd2 car so i dont know much about them but when i look under the car and there is only one 02 sensor. maybe im wrong but i thought obd2 cars use 2 sensors. but i figured the car would run horrible with a missing 02. it runs pretty good though, just a surging idle from the bad egr valve im guessing. what you guys thinking?

 

what ECU is he running? What model civic EX, SI, CX, VX, DX? The OBD2 ECU looks for 2 O2's but one is just for after cat the OBD1 ECU doesn't look for a second O2.

 

its a pr4 obd2 ecu. talked to a guy that helped with the swap. he told me the one after the cat was not needed when you are not running a cat. and that it will only make the cel stay on. is this true? just doesnt sound right to me, but again, im not familiar with obd2 at all.

 

The ECU is going to throw a code with only 1 o2 hooked up. It most likely will not throw a code with no cat. Your best bet is to just switch the car to an OBD 1 ECU. In a 93 you dont need to keep the OBD2 ecu with the swap.

 

if its throwing a o2 code then it cant be running right.either convert to obd-1 or put another o2 in the piping somewhere. i thought only automatics had a egr valve but im not familiar with obd-2.