for all of you that have obd1 cars w/ an obd1 motor.

does the o2 sensor placed before or after the catalyst converter?

the reasoning being for this question is i got an obd1 engine in my EK and i am using an obd2 dx headers built in w/ a cat converter. and my obd2a EX harness only have 1 o2 pluggin socket. i basically did an jumper from obd2 to obd1, so now i am wondering using my obd1 ecu/setup. how should i place my o2.

before of after the cat.

any help gladly appreciated! *thumbs up*

 

sounds like your still using the obd2a harness with a jumper harness for the ecu? if so you only need the 1st o2 plugged in and that goes on the header...so before the cat. if it were obd2, the cat has a bung on it. but you dont need it cause sounds like you made it obd1.

 

ok cool thanks! and yes i am running obd1. i got a jumper for my obd2a engine harness.

another thing, if i plug my first o2 sensor hole (which is the primary) and have an o2 sensor running out of my secondary out of my cat and plugged it into a set up i have on now. will it affect any motor usage?

 

why would you wanna do that? use the primary bung.

 

The primary O2 sensor (which is what you need) has to be close to the header in order for the ECU to make good decisions about the air/fuel ratio.