Over the weekend I received a response to my = question about Digi- operating specs from Mark Keller. Seems he has been running = his WBX in open loop with a voltmeter on the O2 sensor as I have. While I = was out taking the kids to see grandma, I saw that on a high speed = uphill with foot on the floor the voltmeter dropped to 0.00; mixture drastically leaning = out. Got home still pondering this, checked e-mail and = found that Mark had written me about his finding that at wide open = throttle (WOT) the standard fuel pressure regulator can't keep up with what = the engine needs. He says that he acted on R. Lilley's recommendation to install a performance adjustable fuel pressure = regulator with great results. Apparently the stock regulator "tops out" before the = engine has all that it needs. Seems they got their improved = regulators from CB Performance http://www.cbperformance.com/.= Ever been at nearly full throttle and then floored it for = the last oomph? If nothing happens, chances are that you're = running out of fuel. The ECU says "more" the regulator = says "that's all there is". When the ECU says more to a Hi Perf. regulator, it says "OK, how = much?" I am going to try this. I'll report on the results.