Post by
Kompresshun »
https://forums.nicoclub.com/kompresshun-u133574.html
Tue Oct 11, 2011 11:38 am
Welcome to NICOClub!
Is it engine noise that you're hearing? It's possible you might have an exhaust leak somewhere, or maybe have something loose under the hood. I'm not extremely familiar with the Frontier, but our QX4 had an exhaust leak under the car, around the catalytic converter that was quite noisy. You could also have a leak around an exhaust manifold as well. These are just guesses based on my experience, but somebody may be able to chime in soon with a more detailed answer for your vehicle.
If it's just generally noisy, you may try installing some sound deadening material like Dynamat(or similar) inside the cab of the truck instead.