Hi all, new to the forum. I have a 2018 Limited CM 4x4 with about 26k miles. TRD dual exhaust and cold air intake are the only performance mods I’ve done so far. For about the last month, when reversing out of the garage, engine cold, I’m noticing a buzzing/vibrating noise coming from under the truck. Doesn’t sound like the ECM problem people have been having because it’s not coming from the dash (although, I do have thar issue too.). Only happens when the engine is cold, in reverse, and resolves shortly after but it seems to be getting more pronounced. I thought it might be a loose exhaust heat shield but both are tight. Any thoughts before I pay a tech to tell me there’s nothing wrong?