Lean code P0171

The fact that you have a lean code makes us think you have a vacuum leak but that normally comes with a rough idle. However, we still need to check it out. here is a guide that will get us started:

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Next here is guide that will help with finding a vacuum leak:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

However, just because there is a lean code does not mean that we have an air issue. This could be due to a lack of fuel which would fit better with what you are seeing.

Let's check fuel pressure and go from there. Here is a guide for that:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Lastly I attached the testing below that we need to run through however it pretty much takes you through what these guides are doing.

Let us know what questions you have. Thanks