2002 GMC Safari Repair Question
Do you need to reprogram computor if you use a cold air filter system
Clean the MAF sensor and check the fuel pressure
68 questions asked
mass air flow is new so is filter and fuel pump
3 questions asked
The programming was set at the factory. The goal of the intake system is to warm the air so the fuel will vaporize better. Liquid gasoline will not burn or create power. It just goes out the tail pipe wasted. The intent of systems that cool the incoming air is to condense it or pack it tighter. The thought is more air goes into the engine so more fuel will go in and create more power. You can accomplish the same thing by pressing the gas pedal further. Those systems worked on carbureted engines as long as the jet sizes were increased.
You might try playing with the intake air temperature sensor or its location on the fresh air tube. Its readings help the Engine Computer decide how much fuel to command from the injectors. If it's reading colder than normal, the computer knows a lower percentage of the fuel will vaporize so it has to dump more raw fuel in. That is to insure enough vaporizes and burns to prevent stumbling or a hesitation on acceleration. For driving at a steady speed, the computer will not see the exhaust go lean as long as normal when it switches from rich to lean a couple of times per second. That will tell it the mixture is too rich and it will start to cut back on the amount of fuel going in. At that point nothing has been gained except the Check Engine light will be on so you won't know if or when a different problem occurs.
The unburned fuel in the exhaust is supposed to mix with the unburned oxygen in the catalytic converter so it can be burned. That's why the computer is purposely switching the mixture from rich to lean to rich constantly. Burning that extra fuel is going to overheat the catalyst material and melt it eventually. That results in a plugged converter that must be replaced.
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