Alright I am pretty experienced with all sorts of cars and ASE cert. in alot of **** but cannot figure this one out. I have a 99 Honda Civic HX, 5 speed ! I recently put on skunk2 adj. cam gear,gates tb, air mass header ,and 2.25" stainless steel exhaust system (went 2.25" to keep some back pressure). Did everything right the header from holley came with the 3' extention to move the O2 sensor. Ever since then I get code p1163 slow response from primary 02 sensor. The $3000 Snap-On scanner says everything is working on the sensor side and to look for an exhaust leak. The sensor is a 5-wire wideband and I know they are pretty sensative but I have a lift in my garage my buddies and I searched everywhere for a leak and nothing. Every time the light comes on the scanner says it happens in approx 3rd gear-39 mph-21% throttle position and etc. Any suggestions???????? [&:]

 

check the egr setup, you would not think it would effect the o2 sensor but it can,