Why Does Fuel Consumption Increase After Cleaning the Throttle Body?
2 Answers
There are two main reasons for increased fuel consumption after throttle body cleaning: 1. Failure to perform or successfully complete ECU adaptation after cleaning: After throttle body cleaning, the throttle position becomes unfamiliar to the engine control unit (ECU), causing confusion in throttle opening control and resulting in increased fuel consumption. 2. Poor self-learning capability of the ECU in some vehicle models: Due to this uncontrollable factor in certain models, fuel consumption may temporarily increase for a short period but will return to normal after some driving.
I've repaired so many cars before and often encountered cases where fuel consumption increases after cleaning the throttle body. The main reason is that the engine ECU is accustomed to the old throttle opening position. After cleaning, the dirt is gone, the opening changes significantly, and the ECU can't react immediately, leading to slightly more fuel injection and naturally increased fuel consumption. Usually, after driving about 100 kilometers, the ECU can relearn and adapt, and fuel consumption returns to normal levels. Additionally, if the cleaning isn't thorough enough, such as leaving residual cleaner or not wiping it clean, it can cause throttle sticking or inaccurate sensor readings, which may also affect performance. It's recommended to drive on the highway after cleaning to let the engine run smoothly and speed up the ECU's learning process. This is similar to the transition period after replacing new parts. Remember to check the air filter or fuel system to rule out other factors. Overall, it's a minor issue, so there's no need to worry too much.
