Z28-4Ever

iTrader: (4)

i had my headers and y-pipe installed and the car tuned, just a question its loud under the hood, like really loud fans (now i know the fans can be running more because of the header install but why though, because its louder than when it was stock). then every time i shift there is a knocking/ rumbling noise under the car and it does it when slowing down in gear also. just want to know if its an easy fix

joecar

The knocking under the car is the y-pipe hitting the tunnel just behind the transmission.

Without going to poly motor mounts, you may be able to reposition the y-pipe by pulling down on it while the clamps are loose, this will mean leaving the tunnel brace removed.

ramairetransam

iTrader: (18)

how much do you feel the poly mounts in these cars , on my monte i have poly dogbones and you feel it only at idle

Z28-4Ever

iTrader: (4)

so your saying to loosen the clamps pull down and that should fix the knocking when i shift, but id have to remove the brace?

joecar

When you pull down on the exhaust it may now bang on the brace.

omarrakeen

iTrader: (2)

do you mean hitting noises? like the y is banging to the car floor? i mean yea its normal to be louder due to thinner walls.

Z28-4Ever

iTrader: (4)

Yea it sounds like its hitting but it had enough clearence, apprently where the y and the catback connect is positioned high into the driveshaft tunnel so its hitting

omarrakeen

iTrader: (2)

its either hiting the shaft or the floor. go under car and shake the exhaust and check. pretty easy to fix.