Coastie
You probably corrected a leak somewhere after the MAF sensor.
I find the "Haynes" outline on dealing with the air filter very effective: Unclamp the one hose clamp at the throttle body, disconnect the small vacuum hose and the elect connectors. And then lift out of the engine compartment the whole 2-ft-long plastic air cannister...complete with flexable bellows. Replace the filter inside the cannister while working on a work bench....in my case, the driveway.
This method helps to assure that everything gets back together properly ... very difficult if you are trying to do it inside the engine compartment.
I like to lube up all the seal points with Vaseline...which won't bother the CO2 sensors.