changed air filter now not running right
Sounds like you knocked something loose or didn;t connect something back up. Recheck your work, the car should run the same as it did with or without a filter at all. But did you install a K&N filter or oil based filter? If so, then your issue might be that it was over oiled and you contaminated the MAF sensor, got to your local auto parts store and purchase some CRC MAF cleaner and follow the instructions.
Also make sure any vacuum lines did not get pulled off and the filter canister is sealed properly.
Search Toyota 4Runner Questions
Toyota 4Runner Experts