How to- HS headers 01 Maxima.

[BlackBIRDVQ]

Jack up car high enough, and remove both front lower splash shields off the front of the car. Remove the 17mm bolts that hold the motor mounts to the engine- one on the front motor mount and one on the rear one. Then remove the cross member that is held by 2 bolts in the front and 2 in the rear. If you want to do ES motor mounts- now would be the time also. After that remove your stock or aftermarket Ypipe and 0xygen sensors. Remove radiator fans- there are 2 10mm screws on top and 2 on the bottom along with 2 fan connectors. Radiator stays in the car, removed fans give you more room to remove the front exhaust manifold. After the ypipe is off the car, proceed to remove the front exhaust manifold, which is held in by 14mm bolts on studs. Remove the heat shield which is held by 3 10mm bolts 1st. The one stud nearest to the timing chain cover is kinda hard to get out so you need to bend the AC line out of the way. After that I jacked up the engine- tilted it so there is more room to work around the back of the engine- use a floor jack and lift up on the front of the engine to tilt it like this * / *. Remove the engine mount brackets off the front of the engine, and the rear. Rear is a bit tricky to remove, as 2 of the 4 bolts- top ones are behind a little bracket that is in the way. I just jammed a prybar between those bolts and the bracket and bent it down enough to get the bolts out- your bending a part of the engine mount bracket that is bolted to the engine. Reason you bend it so you can remove those 2 14mm bolts out. After you install the headers you can eassily bend this piece back into its normal position. After the bracket is removed proceed to remove the rear manifold heat shield- 3 10mm bolts, and then remove the manifold itself, this is when tilting the engine comes handy so there is more room in the rear. I used some swivels and exenstions to get the bolts all off. After that I reused the stock manifold gaskets- they are metal and won't leak. I put the headers on- front and rear one, but only hand tight. Then I installed the HS Ypipe- dont' forget to remove the 2 12mm botls that are next to the lower oil pan- I forgot bout these, but its not too important. You want to install the Ypipe and THEN tighten the manifolds tight to the heads. If you tighten the manifolds 1st and then try to install the Ypipe you will not be able to get it on. After that you will see that the front 02 sensor - one that is crutial for a/f ratio for the ECU, doesn't clear the compressor. I evacuated the A/C system and removed that line that the 02 sensor hits. Stay tunned for my fix for the AC system. I capped off the compressor and the line so nothing gets inside there. I am almost positive a A/C compressor bracket for a 3.5L will make the HS headers fit the 3.0L without the A/C line/O2 sensor interferrance.I installed quite a few headers in my life on Fords, Chevys, Hondas, Nissans. With the AC evacuation, oil change and tranny fluid change I got the headers on in less than 2 hours.

Tools needed-
PB Blaster- works better than WD40.
14mm swivel
12mm swivel
12mm deep socket
14mm deep socket
10mm shallow 1/4" drive socket
10mm deep socket 1/4" and 3/8" drive.
3/8 drive ratchet- long for more torque.
1/4 drive ratchet for removing the small bolts like on the manifold shields
17mm deep socket- removing the cross member with this.
14mm boxed/open end wrenches- 2 of them.
22mm wrench- for 02 sensors.

Thats all I can remember....

I am not going to go into details on how to extend the 02 sensors behind the main cat, cause from experience will not work properly due to lost voltage/high resistance of the longer wires. I recomend O2 sensor simulator for getting rid of the P0420, P0430 codes and for installing headers.

This install worked on my car, and my car only. I am not responsible for someone elses F-up. Install at your own risk- HS headers will not work with Federal emission 00 cars cause HS headers have no EGR fitting on them.

I noticed gains vs my Cattman Ypipe, dyno charts will soon to come, sound clip video will be done in a hour and I will post it. Happy Motoring.

[chris'smax]

Thanks mike and good write up.

[frankd121]

someone should make this a sticky.