i put a 99 gsr in a 95 civic ex and there was no place to put the o2 sensor know i get a code for it . will the o2 sensor change the performance of the car and where should i put it in the car . i have it on the top of my engine just siting to be placed nicely so where is it going .

 

what ECU? you can have the ECU chipped to remove the O2 sensor reading altogether.

 

no it shouldn't affect the perfomace, if I get it right you are missing the second O2 (the one after the cat). what you can do is either weld on a bung for the O2 after your cat and put a O2 in there, or just switch to OBDI ecu with adapter harness.

 

so you can run obd1 ecu with obd2 dist and harness?

 

Not having an o2 sensor will hurt your gas milage a little. Otherwise your fine. It should be pretty cheap for a muffler shop to weld an o2 bung on your cat (around $20, I'm guessing).

 

u would be running pretty rich. your ecu will be thinking as if you just started your car in the morning, dumping alot of fuel in the cylinder. the ecu would never determine when to switch the mixture from lean to rich, which may do some damage to your cat.

 

If you are throwing an o2 code in a 95ex, I am assuming that you have no PRIMARY o2 sensor, unless you are using an obd2 ecu. Without the primary, the ecu will run in open loop mode.

If you are talking about the secondary o2 sensor, which attaches to OBD2 catylatic converter, than you are obviously running an obd2 ecu, and you need to hook up the secondary o2 sensor.

What ecu are you using, and what code are you throwing? Do you have the primary o2 sensor hooked up to the header?