I had the same problem as you, well similar. What I had was, I passed all categories except low speed NOX. As a matter of fact all other testes were VERY clean. I think the only way I can pass now is it to put the pre cats back on. I have been passing smog for many years but the limits are so tight now and I live in an enhanced area I can't pass any more. I did pass after several attempts (no comment). But in two years, here we go again.
