I had no choice but to order and install a new Y Pipe on my 2005 G35 coupe. It had a major exhaust leak coming out of the Driver & Passenger side mesh joints. It was so unbearable it was not safe to drive. Unless you wanted to be poisoned. Anyways, i installed the new Y pipe myself. I noticed it was touching at 2 points underneath the car. The previous Y pipe was not touching underneath the car because the mesh was so worn out it had major “sag” which allowed it to have more space from the car. I understand i will feel vibration under the seats, but i’m really wondering if this is a fire hazard possibly ? I assume the previous Y pipe was touching just like this one (when it was brand new). I bought the car with the messed up Y Pipe so i wouldn’t know unfortunately.

 

No it shouldn’t touch, and no, it wasn’t touching when new. Something is bent or it’s just a cheap improperly made y-pipe.

 

Just take it down to a muffler shop and have them do a little adjustment on the pipe, that's usually the easiest way to fix something like that. Aftermarket exhaust stuff usually has pretty bad fitment unless you're buying really high dollar complete kits, even then it's not uncommon to need a little pipe adjustment.