I want to do a throttle body coolant bypass on my 04 silverado, I know its cheap, easy to do and make extra power, but will it affect my fuel mileage. A mechanic said that there is a sensor in the TB that reads temp, if the sensor reads a cool temp the computer will pick the info up and make it will run richer. Is there any truth behind this? Any suggestions?

 

To my knowledge the only temperature sensor that the computer reads comes from the MAF sensor. This temperature drop across the element in the MAF sensor is a linear equation that basically equates air flow and density, which gives input to fuel for the proper mixture. The theory being that with colder denser air you dont need as much fuel to get the same amount of HP. That being said, what the mechanic states is exactly the opposite of what really happens. I have thought about doing this mod myself, because in warmer climates of the south there is no need to heat the air before detonation. The reason Chevy has this coolant tube through the throttle body is because they have to design a fuel system that operates in a wide range of operating conditions, from Alaska to Florida and all parts in between. Im no mechanic, but I would think there would be no problem in doing this mod. Please anyone correct me if Im wrong, because as I said, I too am considering doing this mod.

 

actual I have to agree with the mechanic..Cold Air - is more dense and contains more oxygen, therefore requires a richer mixture to achieve the proper air-fuel mixture. I don't Know about your vehicle but many have Intake Air Temperature (IAT) sensors to provide the PCM temperature of the air entering the engine.

 

There is no temp sensor in the Throttel Body.
The coolant is piped thru the TB to help the engine come up to operating temp faster to reduce emissions.
The effect that the heated coolant (and subsequent heat exchange with the incoming air) has on the performance of the engine once up to operating temperature is negligible, but the cooler the air the denser the air/fuel charge and the more power potential.
The electronic engine controls work to keep the same air/fuel ratio regardless of temperature and bypassing the TB will have no effect on economy or anything else for that matter.