When servicing an air filter, sometimes the hoses can come loose. Start by visually inspecting the air box (where the engine air filter is located). Look for electrical connectors or hoses that may have been accidentally disconnected. Continue this inspection down the engine intake pipe. If everything is fine, I would suspect Mass Air Flow (MAF) sensor contamination. When an engine air filter is not installed properly, bugs and other floating debris can bypass the air filter and stick to the MAF sensor, preventing it from determining how much air is entering the engine. The Engine Control Module (ECM) uses this reading to determine how much fuel to add to create the correct mixture. In other words, if the sensor is dirty, the air-fuel mixture may be off. Unfortunately, this condition can also occur simply by removing the air filter when dirt falls from the filter into the intake.
