Okay, so I'm running a OBD0 B16a, converted to OBD1, with a custom wiring harness, in an all custom 99 Civic sedan chassis. The ONLY problems I'm having are codes for O2 and knock. However, even after tuning the ignition timing, the idle now surges just slightly between 1k and 1200. Now, I had an exhaust leak but recently fixed it. Prior to this, it would surge for a few seconds, then settle at 800. Also, when we first built it, all we had was a chipped p28 with a GSR basemap, so the ignition timing had been retarded but ran with no CEL and no problems, we kept it under 6k. Now, I have a p30 and am showing o2 and knock codes, plus the idle is slightly surging. We've adjusted the throttle cable and I tuned ignition timing myself. I am planning on spending the mere $115 on a chipped p28 with a b16a map and having knock and o2 deleted plus a WOT tune for more power. Does anybody have any clues?