Problems related to fuel sensing in a 2002 Tahoe (assuming it's *not* a factory flex-fuel vehicle) would usually involve:
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine, crucial for calculating the correct fuel-to-air ratio. A faulty MAF can lead to poor performance and fuel economy issues that might be misinterpreted as a flex fuel problem.
* Throttle Position Sensor (TPS): This sensor tells the PCM the throttle position, which is used in fuel calculations. A faulty TPS can cause similar problems to a faulty MAF sensor.
* Oxygen Sensors (O2 Sensors): These sensors monitor the exhaust gases and provide feedback to the PCM to adjust the air/fuel mixture. Faulty O2 sensors can result in running rich or lean, impacting fuel efficiency and emissions.
* PCM (Powertrain Control Module): The PCM is the "brain" of the engine. A faulty PCM can cause a wide range of problems, including issues related to fuel delivery and sensing.
If you're having issues that you suspect are related to fuel type detection (e.g., poor performance with different gasolines, but your Tahoe isn't a flex fuel vehicle), the problem is likely in one of the sensors listed above, not a dedicated flex fuel sensor. You need a professional-level scan tool to check for diagnostic trouble codes (DTCs) stored in the PCM. These codes will pinpoint the faulty component.
In short: Take your Tahoe to a qualified mechanic for diagnosis. They can use a scan tool to find the problem, which will be more accurate than trying to guess based on symptoms. Replacing parts based on guesses is costly and may not fix the problem.
