It is possible that the low pressure is caused by a defective cartridge. Also keep in mind that to make sure our faucets are up to code we cannot surpass 2.2GPM or 8.3Lts/Min.
If you would like to increase the water flow, you can start by removing the flow restrictors found in the sprayer head and also in the hose that is connected to your mains.
Attached is a link to a document that was designed specifically for removing these flow restrictors.

This is an easy task that does not require the assistance of professionals. If this does not solve your problem then we can assume it is the cartridge or perhaps something else.
Please make sure your hoses are not bent or kinked as this can cause issues with the flow of water in the faucet.

Conglom Kitchen & Bath Customer Service Team