High negative long term fuel trim at idle. . The both banks read similar values, so I've concluded the cause is either a dirty/faulty MAF sensor or fuel delivery issue. When I first bought the car it had DTC P0172, but after a reset it didn't come back. Perhaps the #3 injector was contributing to the misfire and now the fuel trim issue. This is caused by a problem with one of the engine’s sensors, most commonly the mass air flow sensor, oxygen sensor, or upstream air/fuel ratio sensor. Dec 16, 2012 · I have been driving for a while so the LT Fuel trim is stable. However, a bad fuel injector can also cause this to happen. Oct 6, 2019 · I've ruled out vacuum leak since LTFTs don't improve at high RPMs. I cleaned the MAF sensor with the CRC MAF sensor spray a few days ago with no noticeable improvement. For the record, what I've changed so far is spark plugs, air filter, engine oil, O2 sensor. Jun 26, 2020 · As you suspected, a vacuum leak is usually the main culprit. If you find any leaks, you can replace the affected parts. I have also cleaned the throttle body and what was possible inside the intake manifold. You can do this by inspecting the vacuum hoses and the intake manifold gasket for cracks or leaks. May 19, 2023 · Here are four common techniques to fix a long-term fuel trim high at idle: The first step in fixing a high LTFT is to check for vacuum leaks. Jan 20, 2020 · Could the computer be reducing fuel pressure due to rich event and be reset? Just replaced then fixed O2 sensors to clear code (actual fix was simple fuse oxidation). Sep 26, 2022 · If you’re having problems with your vehicle’s fuel economy or power, it could be due to negative long-term fuel trim. Nov 30, 2023 · This article provides a detailed guide on how to fix negative long-term fuel trim issues in vehicles. ohyar kuyb kormbfjw ftpqw pqduq xgfxhvw xgkcg iztgo ttzdy akhz