Check Engine Light coming on

take a look at your gas cap...and replace it as it isn't behaving itself....also when you gas up stop at the first click or you'll bugger up your canister and ALWAYS have comprimizing the CAT to be the order of the day....requires long hard drivin, like up a mountain to burn it with the healthy equipment installed.

I've seen oxygen sensors fail....and what happens as they get 'gobbled up' by the combustion gasses...leavin a stub...which can still do the job?!...but you haven't been running this NEW sensor long enough for it to be the cause-

Sure do love the air-cooled design...I assume that yours is still this way, and the racetrack ready nature of the beast is on par with the MINI. what I drive and am anxious to see what it can do...right now--not even the S model is prompting the driver to go faster....go faster-

o2 sensor heater may be weak,try a different fuel.if often enough it will bring light on always till reset

The CEL is on and the code says that it's the O2 sensor.... How about replacing the bad O2 sensor? You replaced the MAF sensor instead?

I've had a cracked hose that behaved like what you describe

tenspeed is right. The thing will NOT run right until the O2 sensor is checked and possibly changed-

Try running it hard for a while, burn out the crap ethanol does bad things to allot of things on these cars. Then reset by pulling fuse wait 10 sec. And put back in. It is worth a shot before going through a bunch of diag.

I bought a special socket for O2 sensors and used it maybe twice. It's like an ordinary deep well, but with a slit going up the side for the wire~ I understand your trepidation...but these can be tested still "in play"--what's it doin' to the air/fuel mix? if it's a wrong mix, this little goodie is to blame-----(amongst many culprits on this car)

Tenspeed is right, why are you mucking around with the Mass Air Fuel snesor when the coe is pointing towards the O2 sensor? How about telling everybody what code you got so we can stop guessing as to what's your problem; and start telling you what the True fix should be. There are Hundreds of codes that can be pulled, and without stating what code you pulled, any answer to your question may have you throwing a bunch of unneeded parts and money to correctly fix your problem.

changed out the air injection valves there are 3 cost $250 for parts