2009 Nissan Murano comes in with a check engine light and complaint of hesitation. Scan for codes P0171 and P0174. Check scan data, high fuel trims at idle and off idle. Test drive and monitored fuel trims, rpm, O2 sensors, load PID,and MAF. O2 sensors go over 800 mV at WOT but notice a lack of power. VE test results at about 65%. So with the low air flow reported and the lean fuel trims but high O2 readings, I'm leaning toward a bad MAF or air leak between the MAF and throttle body. Found a 6 inch split in the air intake tube. Replaced tube and fuel trims return to normal, hesitation gone and no more lack of power. VE test now over 80%. While this was a very simple diag, I couldn't have done this 2 years ago. Thank you Paul Danner.
The following user(s) said Thank You: Noah, Andy.MacFadyen
Good work, there is a lot of diagnostics can be done before opening the hood/bonnet. For a while I have been doing a quckie cranking compression test and charging and battery tests by pluging into the cigar lighter socket.
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