Chris, I know you directed your QA to DMC Joe . But you have to have an oscilloscope or a dwell meter to see the 70cps and the opening and closing of the FQ valve. My scope will capture the time of opening and closing so I can check lambda / FQ valve for proper operation. But the trace is to light to put on the web site. Try to find someone with a scope or dwell meter to connect to the diagnostic plug or terminal 17 of the lambda. Then you can see whats going on. John Hervey