Newcastle highway patrol police and officers from the NSW Environment Protection Authority (EPA) carried out testing at Wharf Road on March 8 and 9.

More than 30 vehicles were inspected between 4pm and 12am to see if they exceeded legal noise levels.

An EPA spokesperson told the Newcastle Herald the results of the operation were being reviewed.

Some people could be facing fines if breaches were identified, the spokesperson said.

"We appreciate the community's cooperation to ensure a quieter and safer environment for all," they said.

Police helped identify vehicles for EPA officers to test. The authority is the governing body when it comes to motor vehicle noise.

Newcastle highway patrol Acting Inspector Glenn Swift told the Herald the operation was focused at the foreshore area at Wharf Road, near Nobbys, during night-time hours on a Friday and Saturday.

"The campaign was aimed at targeting noisy and illegally modified vehicles," he said.

"Over the two nights, 30 vehicles, including motorcycles, were tested and inspected."

Inspector Swift said the location had been "an area of concern", which triggered the targeted operation earlier this month.

"It was in response to a number of complaints from concerned community members," he said.

He warned drivers and riders that any modification to to their vehicles was compliant with Australian design rules.

"The ongoing operations mean that the enforcement of illegally modified vehicles will continue," Inspector Swift said.

He said police would continue working with other agencies - like Transport for NSW and the EPA - to ensure cars and motorbikes on the road were sticking to the rules.