Note to the class: When changing air filters, make sure the box is tight

[gtguy]

Mutant Wagon goes in to the dealer's with a lumpy, hesitant idle. It idles fine, then stumbles, then surges, then returns to normal. They hook it up to the diagnostic, call out the local Subaru tech rep (nice guy...loves the P1 wheels and Prodrive exhaust), and they go a pokin'.

Finally, the one tech moves the airbox, and I can see the light bulb come on. Sure enough, he re-fastens it, shoves everything into place, and voila! No more stumble. He cleared the computer of bad learned behavior (it was trying to compensate, and I was running a tad lean), and Mutant Wagon is back, pulling like a locomotive.

The techs there say it's the fastest stock WRX they've ever driven. I'm at a loss, except that I got a good one. I also babied it for the first 1,200 miles or so, adhering to the manual's directives as if they were etched in stone.

So the moral of this story is, if you open that airbox, even if you know about the bottom tab setup (I did) sometimes, you can still hose it off.

Kevin

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