So I've searched the google and the forums with no luck (so if it was answered before, don't get angry :))

Anyways, I just installed an AEM CAI into my 08 TC (http://www.hopupracing.com/aemcoairinsy37.html). Runs fantastic! However 5 minutes into driving the CEL came on. So I turned unplugged the battery until the CEL went off and about 5 minutes later, CEL again. I haven't checked the code. All I could find on google was some guy with an ebay CAI getting the CEL with the code "P0101 CODE =MASS OR VOLUME AIR FLOW CIRCUIT RANGE/PERFORMANCE." I'm not saying thats what I have but thats all I could find online. Again, I'll check the actual code tomorrow. Anyways, everyone on the forum suggested that the MAF was dirty or damaged. I took extra care with the MAF when I was installing the CAI.

Anyone know what it could be?

It looks like that intake doesn't have correct diameter of pipe required for the stock maf. It looks bigger than the stock housing thus the MAF's voltage output to the ECU will be slightly lower and out of it's specified ranges for various throttle positions. I would call AEM on it to verify this is the problem, as in asking them if the pipe is the same diameter as the stock MAF housing.

A way to cure this, besides putting the stock intake on or getting a CEL safe intake, is to use an Apexi SAFC or any piggyback ECU with MAF tuning capabilities to increase the MAF output however many percent it dropped. Bigger MAF housing = less air being metered and less voltage output as a result. If you had a piggyback you would first measure the stock MAF housing inner diameter (2.6" ID) then your aftermarket piece(say 3.0 ID for comparason). Then you measure the difference (2.6 times 100 divided by 3.0)+100=13.4%. So you up the MAF output by 13.4% across the board.

So I've searched the google and the forums with no luck (so if it was answered before, don't get angry :))

Anyways, I just installed an AEM CAI into my 08 TC (http://www.hopupracing.com/aemcoairinsy37.html). Runs fantastic! However 5 minutes into driving the CEL came on. So I turned unplugged the battery until the CEL went off and about 5 minutes later, CEL again. I haven't checked the code. All I could find on google was some guy with an ebay CAI getting the CEL with the code "P0101 CODE =MASS OR VOLUME AIR FLOW CIRCUIT RANGE/PERFORMANCE." I'm not saying thats what I have but thats all I could find online. Again, I'll check the actual code tomorrow. Anyways, everyone on the forum suggested that the MAF was dirty or damaged. I took extra care with the MAF when I was installing the CAI.

Anyone know what it could be?

Possibly an air leak at one of the couplers or at the MAF sensor. Double-check all couplers and the MAFS O-ring. I'd also invest $5 in a can of MAFS cleaner just to rule out a fouled MAFS. I'd also disconnect the negative battery terminal to reset the ECU.

Good luck.