Did you check if your tire got damaged? It might be low on air

 

I had to replace one of my tires a little after I bought the car back in 2005 cause it got punctured. The new one I replaced it with was a little cheaper than the others and had to be replaced since it wore out faster than the others (this was all after the incident). I replaced the tire with the same as the other tires and had alignment and balancing all done. I also usually check my air in my tires often, so I don't think its that. The dealer also thought it might be the worn tire, but it still has the same problem after I changed the tire and had alignment and balancing all done; this was when they suggested the diagnostic for $150 after they said it wasn't the tires. I also had them check under the car, and they said there was no damage. Maybe something got loose?