Police said officers on patrol identified a suspicious Audi A3 travelling in Queens Road shortly before 9pm on Monday (January 10).
A passenger was picked up by the vehicle, which was followed by police and then stopped for driving without insurance, police said.
They said three men in the car were searched, and officers also searched the vehicle for suspicious items.
A Sussex Police spokesperson said: “Officers seized cannabis, weapons, a balaclava and £1,500 in cash in the glovebox.
“The driver, a 22-year-old man, was required to take a roadside DrugWipe test, which he failed.
“A 21-year-old man, a passenger, was searched and found in possession of cannabis.
“The third passenger, a man aged 20, was searched but no suspicious items or drugs were found. He faces no further police action.”
Police said that officers from the Specialist Enforcement Unit and West Sussex Neighbourhood Policing Team then completed searches at the home addresses of the two arrested men.
At one property officers found a ‘significant’ quantity of cocaine and cash, they said.
The Sussex Police spokesperson said: “A 22-year-old man was arrested on suspicion of possessing offensive weapons in public, driving while under the influence of a specified drug, driving without insurance and possession of cannabis.
“He was also arrested on suspicion of being concerned in the supply of a class A drug.
“A 21-year-old woman at the address in East Grinstead was also arrested on suspicion of being concerned in the supply of a class A drug.
“Meanwhile officers also searched the address of a 21-year-old man, where they found weapons which were all seized.
“He was arrested on suspicion of possessing cocaine, possessing cannabis, possessing an offensive weapon in a private place, possessing criminal property, and being concerned in the supply of a class A drug.”
Police said that about £45,000 in cash was seized from the searches at both addresses and the vehicles.
The three suspects who were arrested have been released on bail until February 8 while the investigation continues, they added.
The Specialist Enforcement Unit was established in January 2021 to target offenders on roads.