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'12 IS250 rear pressure vent leaking exhaust

Monsters Inc.

New member
Joined
Jul 5, 2025
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4
I've been really stressed about this 2012 IS250 that's had this same annoying issue... it's secondhand. The exhaust is sneaking into the cabin when the windows or sunroof is open. I tried putting silicone something on the rear vent but well I don't think it's ideal for the long run. I'm wondering if anyone has tried to source a pressure vent replacement made with better materials than the OEM part? Am I on the right track?
 
Yeah, you're definitely on the right track! That rear pressure vent is a known weak spot on the IS250. There's an upgraded replacement out there with better sealing with silicone flaps, just look it up. It's an easy swap and might solve the issue for good.
 
If exhaust is still leaking in with the windows cracked, it might be less about the vent and more about poor cabin sealing or a deeper structural issue, maybe this IS250 had more damage than the seller let on
 
Silicone whatever will not work well eventually in the long run, I dont know how common yet but there are aftermarket or upgraded pressure vents made from more durable materials, like reinforced plastic or rubberized composites
 
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