i just installed the z1 test pipes on my 06 g35 6mt coupe. has a little rattle noise from 2600-2000 when its down rev-ing. didnt know if anyone else heard this too. just wondering if thats how it is suppose to be or if i didnt something wrong. any feed back would be great

 

you could have a loose bolt somewhere that just starts rattling when the right engine vibration hits it. Maybe your o2 sensor is sticking out at an odd angle and hitting something. When you decel in gear your engine torques and that might knock it against the underbody. Test pipes are pretty raspy, so it could even just be engine noise you're not used to hearing. I'd start by putting a wrench on every bolt down there and verifying 100% that they're all tight though.

 

Check the heat shielding. Very possible that its rattling against it

 

i think it is the heat shield on my actually Y-pipe that i need to tack weld down. but good looks

 

I would just take it off completely

 

Just take the whole heaat shiled off the y pipe? The heat wouldnt mess anything up under the car?

 

nope it won't mess anything up

 

cant find a rattle. could it be back pressure or an air leak?