Mechanics

CHECK ENGINE LIGHT, "LEAN MIXTURE,&Q

1999 Lexus RX 300

Engine Performance problem
1999 Lexus RX 300 6 cyl

I'm working on a Lexus RX 300. It came in with a P0171 and P0325 code and the " Check Engine" light on. I put it on my Snap-On OBDII scanner and got a " Lean Mixture on Bank 1" code. I got the P0325 code off, but I can't solve the P0171 fault code. I feel like I've tried everything:

-Knock Sensor
-Oxygen Sensor
-PCV Valve
-Spark Plugs
-Upper Intake Manifold Gasket
-Lower Intake Manifold Gasket
-Coolant Temperature Sensor
-Traced every Vacuum Hose, check for leaks

After all of these repairs, the customer says it runs great, but I can't get the " Check Engine" light to stay off, on top of the stubborn P0171 fault code.

I don't suspect anything wrong with the EGR valve because it idles well. My scanner should give me a code as well. I don't suspect the MAF sensor either because again, no codes show up on my scanner.

Do you have any suggestions?
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Tayagsautorepair
October 19, 2009.



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