P0172 Fault Diagnosis for 2005 Saturn Vue 2.2L 4-Cylinder: Sputtering on Highway, No Black Smoke
Hello everyone! I've read numerous posts about the P0172 code, but none match my exact symptoms. I own a 2005 Saturn Vue with a 2.2L 4-cylinder engine. The issue began when driving on highways after 20–30 minutes of operation — the car starts to sputter, feeling like it's choking or coughing. I can still accelerate, but it’s very frustrating. The sputtering only occurs when accelerating; once I release the gas and coast, the problem stops completely. As soon as I press the accelerator again, the sputtering returns. However, once I exit the highway and reduce engine RPM to lower speeds, everything runs smoothly. My car has never stalled, and idle is perfect — it sits comfortably at 700–800 RPM, almost like it's not running at all. I’ve seen no black smoke, especially now that it’s warming up outside. The P0172 code persists constantly, and I’m finding dealerships too expensive to visit right now. So, where should I begin? What diagnostic tests or checks can I perform to identify the root cause? Thanks in advance for any advice!
I recommend checking the oxygen sensors or inspecting the fuel pressure regulator for leaks. Without detailed diagnostic data, this could be a guesswork situation — proper diagnosis is essential before replacing parts.