Back out of the driveway. Hit the garage door opener. Shift into first. Smoothly let out the clutch and slowly roll on the gas. Clutch. Into second. Clutch. Gas. Wait a few seconds… punch it! “Growl!” goes the engine. “Whoosh!” flies by the world. “Grin!” goes the face. The Bimmer is back.

After fighting a mysterious intermittent check-engine light for the last year, I finally won the battle. The problem turned out to be a degraded mass airflow sensor (MAF). The MAF measures the amount of air that is coming into the engine, and the engine’s computer uses that information to decide how much fuel to inject, among other things. Besides the annoying dash light, the faulty MAF was causing a serious loss of power between 3500 and 5000 RPM, which I had chalked up to bad spark plugs — until I changed the plugs and the problem remained.

A five-minute session in the garage was all it took to swap in a new MAF. I must admit to cheating a bit on the replacement. The genuine BMW replacement MAF is about $400, and that’s just insane for what is essentially a piece of plastic with a wire running through it. Fortunately, the BMW MAF is actually made by Bosch, and that particular model is used in a number of other cars. One of the other cars happens to be the Volkswagen Jetta MK4 VR6. With that information, I went to the VW dealer and exchanged about $100 for a VW-branded Bosch MAF. One hundred dollars is still outrageous, but it’s better than four hundred dollars.

After popping in the new MAF, I backed out of the garage as described in the opening. Excuse the vulgarity, but damn that car pulls hard now. It feels like it did when I first got it: insane acceleration with unbelievable torque through the entire rev range. No service lights, either.

There’s nothing like the feeling of absolutely nailing a problem except the feeling of a fast car in its element.