The MAF is sandwiched between the TB screen and the TB. It takes two screws to remove it, but make sure you disconnect it first. I can't remember what size they are but they are star headed bolts for sure.

late_model_maf-574x467.jpg

3755LT1_MAF_2.jpg

 

Found it. thx. See my posts before yours...Im not sure if its the MAF now.

 

Here are the codes I pulled off of it prior to me changing anything.
: PO341 CMP Sensor ciruit out of range
PO420 Catalyst effiency Low Bank 1
P1571
P1811
U1040
U1301

 

You'll need a scan tool to check the output of the MAF sensor and it displays the output in grams per second. With the engine warmed up to normal operating temp, the display should read approximately 4-6 grams/sec. When the engine is revved up, the values should rise quickly and remain steady at a steady engine speed. Before checking the MAF sensor operation, check the voltage supply and ground circuits. Disconnect the electrical connector from the MAF sensor and connect the + lead of a voltmeter to the pink wire terminal and the - lead to the blk/wht wire terminal at the harness connector. Turn the ignition key on, the voltage should read approximately 12 volts. If the voltage is incorrect, check the circuits from the MAP sensor to the power distribution center and engine ground point (don't forget to check the fuses first). If the power and ground circuits are good, check the MAF sensor operation with a scan tool. If the MAF sensor does not respond as described previously, replace the MAF sensor.

Per Haynes manual.

Do you have a high flow downpipe installed? If you do, the pcm will throw the PO420 code.

 

P0420 Catalyst System Efficiency Below Threshold (Bank 1)
http://www.obd-codes.com/p0420

P1571 Traction Control System PWM Circuit No Frequency

P1811 Long shift and maximum adaptation limit reached

U1140 Loss of serial communications for class 2 devices
U1301 Class 2 Short to Battery

I'd check your battery connections, along with the connection to the PCM before you go ANY farther. You've got a bad connection somewhere. Check the ground cable. You've got an electrical gremlin, and I hope it's that simple.

 

I do not have any mods other than a CAI by K&N.

Ok, Ill check the battery and connection to the PCM. I already put a new MAF sensor in, but only drove it for about 15 mins. It didnt cut out, but I want to test it further before accepting that the problem has been solved. Thx for the codes.

I let ya know what I find. Thx for your help guys.

 

Besides checking the connections check the fuses as well. GM is notorious for their electrical gremlins and can/will drive you crazy looking for the fault, as well as emptying your wallet.