Dec 16, 2012 · Running too rich – High negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative …

Apr 26, 2012 · However, I thought that fuel trim isn't used when the vehicle starts (not until closed loop operation). 1) If the engine is really cold and the air is more dense, shouldn't it still start okay if the …

May 19, 2019 · Fuel trim issues: Resolved by carefully comparing both bank1 and 2 and viewing live data with two separate scan tools. Found small vacuum leak at Evap sensor mounted at center of …

Jun 29, 2016 · LTFT (long term fuel trim) should not change instantly, it is a learned response that happens over time. If the STFT stays consistently negative or positive for a long period of time.

Jul 2, 2023 · Now I need to diagnose this issue and I have had a look at tons of things like injectors, fuel pump (which I replaced with a Chinese cell which seems to have fixed at least the roughness of the …

Dec 3, 2020 · Of course your fuel economy would be poor, the ecu is adding 20% more fuel than normal. Your engine is burning oil which can upset the AFR sensor slightly. Have you contacted a …

Mar 6, 2018 · Hi there, I wanted to try and confirm a diagnosis with my fuel trims. I have negative fuel trim (-14 on the long term, rich condition) I noticed when I let go of the throttle and coast, stft goes to 0.

Jul 16, 2019 · As mentioned above injectors could be the issue, a leaking injector could also explain the lower mileage and maybe the dieseling. Using a fuel pressure gauge and seeing that the fuel rail …

Jul 11, 2013 · There is a parameter called fuel trim cell and another called fuel trim index. Many of the DTC codes for lean or rich mixture will use fuel trim index as the definitive parameter. Though I …

Jul 4, 2023 · Have you been able to fix Negative STFT? I have the same STFT in my civic 2010. As soon as i remove the dip stick, the engine load goes back to 28-30% from 36-38% and fuel trims to …