I have an 05 civic and one of my friends just parted out his civic and I got some no name brand Catless headers. They have the two spots to put 02 sensors in. I know that I will throw a check engine light thats fine I have until next july for inspection but if I run catless headers I heard my car will run lean. Will this mess up my motor with no tune? also besides sound will it have any horse power gains without a tune?