2004 Lexus RX330 V6 with engine code P0171

Question

My wife got gas on Tuesday evening. Wednesday morning the start engine and various lights came on, the codes were P0171 and P0303 what is the most likely cause? 2004 Lexus RX330 V6 60,000 miles

Answer 1

Hi there,

It's quite possible the issue is a leaking intake manifold gasket on cylinder 3. This could cause the P0171 lean mixture code and also cause the P0303 cylinder 3 misfire code at the same time.

Answer 2

Besides what @Carguy1 wrote, I will suggest driving your vehicle for a couple of days and then refueling with high-octane fuel, it is possible that you got bad fuel.

P0171 Lexus Code - Fuel Trim System Too Lean Bank 1
Read more: https://www.autocodes.com/p0171_lexus.html

P0303 Lexus Code - Cylinder 3 Misfire Detected
Read more: https://www.autocodes.com/p0303_lexus.html