What spec? How did you measure it? In what section of the Haynes manual?Could??? What fuel pressure did you measure?No, if the FPR fails, it's more likely to have a rich condition.Nothing tell the sensor - the sensor senses the oxygen level in the exhaust. If that level is high, the EEC interprets that as the engine running lean. And the engine MAY BE running lean. But the oxygen level can also be high due to exhaust leaks, which is more often the cause of a lean fault than the engine running lean.