Exhaust leak near headers
 

Hello all,

Recently I’ve been having issues with my 2016 BRZ. I’m confident I have an exhaust leak near my headers however haven’t been able to confirm this as I am away for work and won’t be home for another month. The car “sputters”, for a lack of better term, when starting from cold and has delayed throttle response when starting from a stop. I’ve driven this car for 5 years now and I know where the bite point is and is and I have to feather the throttle a little more to get it going. However once the car is fully warmed up, it drives fine with no obvious issues making me believe the leak is sealed due to the metal expanding when hot. At the moment I park my car in a parking garage overnight and when I start the car the in the morning, no sputtering, however after work and the car sitting outside for ~9 hours, it sputters when starting. I’m in California so the car isn’t cold. I do have aftermarket headers but they’re only 3 years old so I’m hoping they’re not cracked. I’m very confused as to what is causing this anomaly with the leak depending on where the car is cold started and would appreciate any possible insight into this. I included my mods list and a sound clip of it starting after work

Thanks in advance

Mods list:
Ftspeed UEL headers
Nameless performance catback exhaust
Ptuning flex fuel kit + stg 2 tune

https://youtube.com/shorts/vu5KL40DR...USsKwGs8fNzRJA

Get under and look for signs of leaks. Dripping water on cold-start, cracks on joints/pipes, loose fasteners, or sooting

• You can also spray some soapy water, but you have to do it close to cold-start or else it will vaporize instantly and won't give you any indication (also thermal shock not good for pipes)

You have a flex fuel kit, so it could be something related to your fuel, fuel map / response

Delayed throttle response could also mean MAF, dirty throttle body, or bugged idle learn