I HAVE A 98 CIVIC EX I PUT A DC SPORTS HEADER,A HIGH FLOW CAT,AND A TANABE RACING MEDALLION EXHUAST ON IT.BOTH O2 SENSORS ARE HOOKED UP, I HAD TO PUT THE ONE IN THE CAT MYSELF BUT ITS IN AND NOW I GOT A CHECK ENGINE LIGHT AND IT SEEMS TO BE RUNNING RICH WHAT CAN I DO TO FIX THIS AND GET A LITTLE MORE PERFORMANCE??

 

What engine code did you get with the check engine light? With my dc 4-1 header and hks hiper exhaust i was getting a p01333 i think. The dealer told me that since my car was making extra hp is was using more fuel so that the ecu thaught that there was a problem with the 02 sensor. I just put in a new one a year ago(350 from the honda dealer). Also I think that my car is running rich too. I'm going to put a skunk2 intake manifold when it comes out to hopefully lean out the fuel a little. The only real way to fix the car from running rich is to go and get it tuned. I started to get this problem about 2 months after puting the dc header. I called up the company and asked for a new wiring harness. I think that might be the problem. I'll let you know when i change the wire.