So I get a cel 31 which is the maf, but it only comes on if I go highway speeds. If i clear the cel, it wont come back for weeks unless i go highway speeds. I get my multimeter and try to check and all the voltages are good, except i get 19ohms as the resistance. What is the resistance supposed to be? If it matters the weather was 42F.
Thanks guys!

 

Whether it's an SC300 or SC400, this is correct. Make sure you are testing the MAF/AFM on the right terminals. Compared to this picture, your MAF/AFM might be fine...what car is this?