sman789

You may have seen the guy on this board selling home-made headers that (if you want) go straight to the y-pipe.

I'm about to buy it but want to know how hard this will be to install. The car is a bone stock 90 auto gxl and i'm trying to find a write up on the install of a header.

i heard that taking off the old one is easy but taking out all the old stuff is hard (like what)

is there any small things i need, gaskets etc..

SureShot

Be careful with the exhaust manifold nuts & studs.
You don't want to snap off a stud.

Only use 6-point sockets (not 12 point) on exhaust bolts.

PB blaster or other penetrating oil helps.

You should be able to re-use the manifold gasket.

If the exhaust ground strap is missing, replace it so the O2 sensor will work right.

casio

i thought O2 sensors were self grounding, the extra ground just helps. (??)

Cory Simpson

If you don't have a car lift, or a way to jack the front of your car up pretty high, I'd think a 1 peice header that goes all the way back to the cat-back will be hard to get in place.


Just be glad you don't have a Vert, there is an extra cross member on the front sub-frame, that makes it twice as hard to get the header in place!

sman789

we do have a lift

SureShot

It grounds on the exhaust system by way of many rusty bolts.
My stock GXL had 4 or 5 factory ground straps.

casio

yea, i added a ground strap awhile back (before my car died), but it came undone (or broke). nonetheless, it was further down the exhaust. is there an ideal place for a ground strap (or5) for the O2?

Kenteth

And I hought the 02 sensor didn't even need a ground...

(heat and catalystic cause electron movement on an electrode...)







EDIT:

I thought the exhaust ground strap was to eliminate engine noise from the stereo system...?

SureShot

Anywhere near the O2 bung is good.
The firewall to bellhousing ground is the next closest, but if it's not shinny bright perfect the O2 reference will float.

casio

there's just not many great grounding places on the exhaust. i have a racing beat (uncollected) header to a 2to1 custom pipe to an old RP (?) exhaust. its been awhile (over 6 months) since i've been under my car, so i cant think of any good spots on the exhaust, especially near the O2 bung.
as for not needing a ground, i've never heard that. i thought i was told (in class) that they were self grounding. do 4 or 5 wire O2 sensors have a wire that is specifically a ground? or are all the wires reference/power ?

Kenteth

I thought 4-5 wires had two leads, a power and a ground (power and ground for a heating element)

casio

oh thats right, they heat themselves, dont they? i'm sure the burning hot exhaust assists that.
is 'lead' another name for reference? fancy.

Kenteth

althought it could be, reference is probably the more correct term :/

SureShot

Without a handy ground bolt near the O2 sensor, you just fall back the the firewall to bellhousing ground.

No biggie as long as it's solid.

The extra wires on some models are for a heater - but you already knew that.

casio

i knew, or remember hearing, about their ability to heat up, but i'd forgotten. its one of those things that seems right, but you arent sure.
i would also like to point out that this is my only FC and the only FC i've really gotten to work on. with that note, what firewall to bellhousing ground are you referring to? that really small(thin) one that has a (slide on) clip on the end?

Kenteth

I melted that small thing after my tranny swap. I ended up adding a big 4awg wire for a chasis ground... much happier

SureShot

Yup - That cheezy clip is your ground closest to the ECU.

If the primary cable from the battery to the starter gives any trouble, that little clip must carry all electrical loads in the car..

casio

just making sure i was thinking of the right wire. that thing was never hooked up as long as the car was running. i always figured it was a ground to something, but i never thought it was to the chassis. i have extra big-*** (battery sized) ground wires, maybe i'll replace it with one.
i wish i had a picture to make sure it was the right wire, but i imagine it is. i dont know of any other grounds with that female end on them. i never knew what it clipped though. if someone could explain where or post a pic, that would be spectacular. it doesnt really matter if i were to use another wire, but i'm curious.

Kenteth

theres a male spade that is bolted to the firewall on the.. i think mid passenger side IIRC

Kenteth

Notice how it looks like nothing has been hooked up there for along time... heh I couldn't even find the wire thats supposed to go there, so meh

sman789

heheh....topic drifted away