I recently put a header on my 97' Civic LX. The stock manifold had an O2 sensor on the top and one on the bottom of the cat. converter, but the header only has one O2 plug slot and was wondering, if I tapped a new hole with the cat. converter missing, would it lower power much? The check engine has been on since the stock manifold got a crack in it and when the header was installed the light stayed on. that O2 sensor is just hanging around.

 

Wrong forum.
Post your Civic 92+ questions in the EG forum.

Anyway, get your **** hooked up right so it runs right.
Nothing too dificult in figuring that one out.

 

your car is obd2... you have an o2 sensor reading after the cat/in the cat, correct? if you eliminate the cat and/or that o2 sensor you're going to throw a CEL. you need a cat and o2 sensor.

 

secondary o2 sensors are to monitor the Catalyst efficientcy and has nothing to do with engine performence. If your engine is running poorly it's not due the secondary o2.

 

if the secondary o2 isn't getting "correct" readings you will get a CEL....

if you have an obd2 car and have an CEL then you won't pass inspection.

as for whether or not the car will go into "limp" mode i'm unsure but if you have obd2 just get a high flow cat and be done with it.

 

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