My friend who's a mechanic can hear an exhaust leak where hes guessing is by my y-pipe based on sound im a new car guy so to be honest didnt really notice anything until he said something. He said its like 100% very minor but im young and just started full time so 400$ to fix the leak is not much but still hurts a bit. Im worried mostly about my MPG as gas in canada right now is ridiculous not so much about preformance because i plan on getting a custom exhaust. I want to know if its okay to wait till i get a custom exhaust or if i should get the leak fixed pronto. Is it olay to leave it is this a horrible idea to leave it? My delema is were not 100% sure if its an exhaust leak i just bought the car quite literally yesterday. And had it saftied by the dealership. Exhaust leak is part of the safety so it shouldve been fixed if it is an exhaust leak and is under the 36day or whatever it is warranty, the dealership is an hour away from me and is a pain in the butt to go to. They are lenient and probably would just send the money or something if I could prove its an exhaust leak. Im just sort of in the middle shoukd I go to the dealership to check if it truly is an exhaust leak and have them fix it, bite the bullet on the hour long drive. Or go to an exhaust place and have them look at it and if they confirm its a leak call the dealership and get them to pay for it. Any insight would be helpful thank you in advance!

 

Why does your friend think it's an exhaust leak? VQ's are infamous for having a "hiss" when letting off the throttle at higher rpms, as well as the engine itself being a bit noisy in the cabin (especially if you're lacking the splash shield underneath the engine, so the sound bounces off the ground).

If the dealer checked the vehicle and missed an exhaust leak, I'd be very suspicious about the quality of their work (assuming this is an Infiniti/major OEM dealer; all bets are off with non-OEM dealers, good luck getting them to cover stuff). Assuming a gasket isn't blown, the only other place (assuming the pipe wasn't just scraping the ground for weeks) would be the flex pipes, either due to age/movement or abrasion.

You should (a) have your friend sit in the car to operate the throttle and get a flashlight/yourself low and see if you can hear/see (use your hand or a sheet of paper) to see if there's actually air coming out of the exhaust, or (b) get the car up on jackstands and do an inspection that way.

You should be able to get either a used HR Y-pipe or a middling quality aftermarket one for a lot cheaper than $400, and it's a super easy install with basic wrenches and some jackstands.

Worst case scenario, driving with a minor Y-pipe leak is not really a concern; you'd have to have shredded flex pipe and/or good sized holes to cause a concern with fumes while idling. I drove for a month or two with busted flex pipes and (unknown at the time) a cracked high flow cat weld, and I only ever smelled fuel when I planted the pedal. But jack the car up, do some brief checks, and if you see evidence of a leak, take it back to the dealer.