This can be a vacuum leak, low fuel pressure/delivery, bad fuel injectors or a bad. Please go over this guide:
https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers
I have seen the MAF sensor cause this problem.
The P1274 and P1283 codes in a 2004 Nissan 350Z are related to the air-fuel ratio and indicate issues with the Bank 1 or Bank 2 Air-Fuel Ratio (A/F) Sensor. Here's some information about each code:
P1274 - Air-Fuel Ratio (A/F) Sensor 1 Lean Shift Monitoring Bank 1
P1283 - Air-Fuel Ratio (A/F) Sensor 1 Lean Shift Monitoring Bank 2
Use this guide when the engine is cold only:
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge
The fuel pump could be getting weak as well. Check out the images (below). Please let us know how it goes
Images (Click to make bigger)
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Tuesday, July 11th, 2023 AT 5:35 PM