Thanks guys :) I've got tons of responses explaining the real way the HL and CL works for closed loops. I changed the HL down to 1050 and CL to 875 since it idles better in open loop. The car idles noticeably smoother at 1.74ms than 1.66, and when the DFI takes out even more to get the 02s down, well... doesn't idle as well. Thanks again :) A.