Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Recently had a P0171 and 174 lean bank 1 and 2. Freeze frame data showed idle when code was set. Smoke test indicated intake manifold vacuum leak. After new manifold gaskets and smoke test again no more vacumm leaks but still had a P0171 and 174 codes come back. Freeze frame data this time showed 1800 rpms when code was set. Fuel pressure check was consistently at 59 psi. Ended up being the MAF Sensor. Fuel trims are with in 10% and car drives well.
Heres my question, while viewing the live data on the scanner my up stream AF Sensors show .037 volts on both banks at idle or cruising. WOT it decreases to around .025 and when i let off the gas they usually go up to around .060 volts. Also both banks show a Lambda of 0.002 and never move.
I have used another scanner and it shows the same values.
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