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Header install vibrations

willie14

willie14

New member
I just installed SD headers on my 98 grand prix and I got tell ya after all the tweakin to get them to fit right holy S**t what a difference. My only prob now is the car has mad vibrations while in reverse. Anyone else experience this? I've swaybar clearence and o2 clearence but how could that crappy o2 sensor vibrate against the firewall lil that and still be fine? Solutions anyone before I start tearing this thing back down to figure out its my only beef with this install.
 


i moved my o2 sensor. or you need to beat the fire wall more to clear it. mine bent from hitting, and soon went bad.
 
So u thinkin that's what it is? I thought about moving the bung before I installed but I got too anxious n wanted to install them. They look amazing for price. No rtv, changed some clamps but no major leaks. Slip joints fit great. I just thought it weird with the vibration. I thought I pounded enough clearence but I guess not. How much do I need for it to clear enough?
 
from pics ive seen a bout a inch deep the length of the o2 sensor.

you can have some one put the car in reverse and watch the o2 hit the fire wall from the top side. to confirm it.
 
mark around the o2 with a marker, then pound a dent in. you'll need a air hammer to do it now with the header in place.
 


I had pretty it pretty easy enough just gettin under the car n pounding it out with my brass hammer and a long chissle. I actually just thru a code this morning driving n I'm going to assume its because I have no cat right now
 
willie14 said:
I had pretty it pretty easy enough just gettin under the car n pounding it out with my brass hammer and a long chissle. I actually just thru a code this morning driving n I'm going to assume its because I have no cat right now
Click to expand...

Your gonna be running rich untill you fix that
 
being a 98 you dont even need the rear o2 sensor. im guessing you plan a pulley drop and a tune right? or why else install headers lol

in the tune have the cat code and rear o2 deleted. done deal.
 
Why wpuld I be running rich tho? All the rear does is check cat performance? I thought the front adjusts my fuel trims correct? If anything after my headers put on I be running leaner than normal
 


should have done the header install with the top swap then, much easier to get them in when the rear head is off.

now you need to unbolt it all again when you change the heads.

a 98 wont over fuel it. its the 01 up cars that will. they need a cat test turned off in the tune. i got a 98, rear o2 aint even there, plugs just tucked up in the heat shield.
 
Yea I was thinkin bout that but i dont have all the parts for my top swap yet but its no big deal its not like the rears gonna move when I unbolt it just like 10 mins of extra work. All I've Hurd about these is you lose a ton of power on an NA setup but I feel like I've gained all the way around. I thing since the primaries are 1 1/2 and not 1 3/4 u don't lose so much on the bottom
 


boosted cars feel weaker with headers and a stock pulley, with a stock pulley your boost will drop up to 2 psi, cause it flows that much better.
 
I think its just all about the tune. I fixed that vibration issue fyi and went to my buddys who tunes for a living and we were going Thru all my table settings vs my future boosted setup tune and with what I plan to run with the rockers, 3.5 pulley and meth injection I should be pullin about 10 psi as long as my maf calibrations are on point
 
my top swapped set up dont like boost. 3.2 and 10 psi = about 13-14º wot timing to not knock. back on the 3.4 im at 18º wot now. some top swapped cars like the boost, some dont. the track will tell my story as its been ran on the 3.2 already.
 
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