No.

This cold air intake comes with an aftermarket filter from the manufacturer.

Yes. The CAI from Volant is legal in California.

2004 - 2006
Dodge
Ram Pickup
* Sub Model: 1500 SRT-10
* Engine Type: 8.3L V10
* Fuel: Gas
Performance Cool Air Intake Kit ZX278766
And it does use the hood scoop.

To use the scoop for extreme offroading through streams or creeks at a high rate of speed is not recommened. This unit is made for track use only.This accessory scoop maintains the horsepower gain and increases mpg only on highway driving

This product is 50 state legal and Carb Exempt.
As well it does retain use of the Maf

At this time we do not currently offer this intake on our webpage. Please check back!

LT and WT are trim levels on the Colorados. Usually companies will use the designations to determine if you have the I-4 or I-5 engine (inline 4 cylinder or inline 5 cylinder). This is actually a bad thing because they assume that only the WT (which stands for work truck, basically your base model) has the 4 cylinder and that the LT (which stands for luxury touring) has the 5 cylinder. This is wrong as the LT can have either motor.
Now specifically reguarding your Z71, on colorados the LT 2LT package is the Z71 with the I-5 (if 4x4 is chosen) vs the LT 1LT package which is the standard 4x4 with the I-4.
Now for all your 2WD guys (and gals) its pretty much the same. If you have a WT its a 4 cylinder, LT 1LT still a 4 cylinder, LT 2LT its a 5 cylinder.
Now if you arent sure what trim level you have and dont know what to look for under the hood, thats ok, there is a very easy way to tell. Pop open your glove box and take a look at the inside of the door panel. There is a list of codes called RPO codes. These list your option packages using 3 letter codes. If you noticed on the LT packages I mentioned there was a 3 letter combo that followed. Those are RPO codes for those packages. So if you were to look these would be the codes you would be looking for.
WT 4 cylinder = (code unknown, possibly no code)
LT 4 cylinder = 1LT
LT 5 cylinder = 2LT
LT 4x4 5 cylinder = Z71 (and possibly 2LT)