pacesetter Lts installed now knocking.

**krug07** · 09-28-2008, 03:34 PM

i installed pacesetter Lt headers and now im getting a bad knock like there hitting under the car. you can feel it and hear it. how do you fix this? also on my way home i got on it a little to pass someone and the ses light started flashing. i dont know whats that about. i took the egr off haven't plugged them yet. also the 02 sensers are hanging we forgot to zip tie them if thats what i can do with it or tuck them somewhere? any ideas on all this?

**krug07** · 09-28-2008, 05:35 PM

anyone??

**david_viny** · 09-28-2008, 05:49 PM

IIRC I think 01-02 LS1's dont have an egr valve. And do you mean the front O'2 sensors are not hooked up or the rear? Fronts not hooked up could mean trouble. Do you have the rest of the exhaust hooked up?

**Bouvers** · 09-28-2008, 08:09 PM

the knocking is likely the y pipe this occurs quite often it either has to get fixed with some serious bending or placing rubber between the exhaust and the body where its hitting.

make sure you delete the rear o2's and make sure your front o2's are hooked up...

**nhraformula** · 09-28-2008, 08:22 PM

take it to an exhaust shop and have them heat up and bend the y pipe downwards

**Bouvers** · 09-28-2008, 08:23 PM

+2 if you want it done right

**krug07** · 09-28-2008, 10:11 PM

the rear o2's are delated the front are connected but the headers came with longer wires for the front 02 sensers so i dont know where to place them they are just hanging and getting on the headers which we put alot of electrical tape on the wires. but it needs to be off the headers and out of the way or its going to be burnt up in a matter of time.should i ziptie them to something under the car? and any idea why the SES light flashed all the sudden? the rest of the exhaust is connected to the y then a cutout and i have hooker catback exhaust also.

**UTVols98** · 09-29-2008, 12:30 AM

The exhaust rattling on the floorboard could be setting off the knock sensor causing your SES light to come on.

**JoshieDoom** · 09-29-2008, 01:19 AM

Flashing SES=Misfire

**Blackout01** · 09-29-2008, 08:12 AM

Yeah I just did the same install, mine is hitting something under the car too. Going to try to do something to fix it. I was thinking the same thing with the rubber shim.

**Blackout01** · 09-29-2008, 08:21 AM

So you guys suggest taking it to an exaust shop and having the y pipe heated and bent down more than just puttin a rubber shim in it? I don't really like the idea of heatin up the Y pipe and bending it down, sounds like it not only cost me ground clearance but also weaken the durability of the pipe.

**krug07** · 09-29-2008, 03:13 PM

im curious also about them bending the y by heating it up.

**BMJ99Z28** · 09-29-2008, 05:29 PM

I've got the same problem thinking of trying polyurethane motor mounts.

**WS6ICK2K** · 09-29-2008, 06:07 PM

Bending the Y pipe is very common. They just bend it down slightly enough to stop the knocking on the bottom of the car. It will not compromise ground clearance enough to worry about, even on a lowered car. I had to zip tie my 02 senors also, just use your imagination to get them away from heat its nothing critical.

**Bouvers** · 09-29-2008, 06:19 PM

Originally Posted by Blackout01

So you guys suggest taking it to an exaust shop and having the y pipe heated and bent down more than just puttin a rubber shim in it? I don't really like the idea of heatin up the Y pipe and bending it down, sounds like it not only cost me ground clearance but also weaken the durability of the pipe.

not really think of all the other f-bodies out there with a y-pipe... they all have the same amount of space between the midpipe and floorboard as what you want to accomplish to stop contact... you won't have any less clearance then what is actually intended...

**nhraformula** · 09-29-2008, 07:42 PM

Originally Posted by Blackout01

So you guys suggest taking it to an exaust shop and having the y pipe heated and bent down more than just puttin a rubber shim in it? I don't really like the idea of heatin up the Y pipe and bending it down, sounds like it not only cost me ground clearance but also weaken the durability of the pipe.

i did the rubber thing at first and it vibrates.
i had my y pipes heated and bent over 3 years ago and the pipes were not weakened.
they only bent them like half an inch downwards so i didnt lose any clearance

**harri_z28** · 09-30-2008, 06:58 AM

can you have them bend them with them on the car? or tdo you really gave to take that damn y-pipe off again?

**Blackout01** · 09-30-2008, 07:04 AM

Yeah seriously, it will be cost way too much money if they got to take the Y pipe off, and where exactly does it need to be bent?

**harri_z28** · 09-30-2008, 07:30 AM

like right under the driver side floorboard.

**nhraformula** · 09-30-2008, 03:09 PM

Originally Posted by harri_z28

can you have them bend them with them on the car? or tdo you really gave to take that damn y-pipe off again?

a muffler shop will put your car on a lift. they then get underneath the car with a torch, heat up the y pipe (1 inch wide if that) then bend it downwards with a crobar or whatever.