uptownsamcv

I took the time today to install the VQ30 exhaust manifolds and Warpspeed Y-pipe on my 02 3.5 6 speed. headers were looking way too pricey and I read that the VQ30 exhaust manifolds flow better than the VQ35 ones. I used the 4th gen exhaust manifolds and 4th gen Warpspeed y-pipe. I also purchase multi-layer exhaust manifold gaskets as well as 2 2002 Nisan pathfinder upstream left side oxygen sensors that have longer wires and use the same bright blue connector. with this install, I won't be able to install rear O2 sensors on the Y-pipe cause it only has 1 bung per each bank for a primary O2 sensor. I'm just going to connect them and put them in a spacer with dimes siliconed over the hole and hope the engine light doesn't come on. I'll wire in a resistor later on if I have to. I also had to get a plug for the EGR fitting, Nissan OEM part # 14052-21R00




this was not a hard job as I first thought, it was just really time-consuming, plus I had to leave and take care of other unrelated things . I know a lot of guys get intimidated when it comes to installing headers on these cars but here are a few tips to make it easier.

first, remove the Y-pipe along with secondary O2 sensors than the center beam.

next remove the rear pre-cat. 2 of the nuts have to be removed from the top side. I used a super long 1/2" drive extension with a 14mm to get at those from the top side.

next , the rear bank exhaust manifold: what makes the rear bank hard is the tight space as well as the engine mount bracket on the block.

in order to make space, you want to tilt the front of the engine up. I took the front mount off the beam and attached it back to the front mount bracket then raised the front of the engine with a jack.


the rear mount bracket has a thick flap blocking it's top 2 bolts. use a long 1/2" drive extension and bang it upwards with a mallet. once you moved it enough you can use a short 14mm with a u-joint and extension to get at them. what I did was modify the bracket once I had it removed. I used a Dremel and cutting discs.

before


after


once the rear bracket and rear pre-cat is off, you will have plenty of space to get at the rear exhaust manifold with a deep 14mm socket and extension. I think I used a 3" extension.

the front one is easy, I didn't even have to remove the front pre-cat or mount bracket. I just removed the jack from under the front mount and removed the radiator fan assembly. the nuts are easy to get at except for one by a metal A/C line that you will have to bend, bend it slowly and be careful! be careful not to damage the radiator as well..if any exhaust manifold studs come out attached to the nut I recommend taking the nut off those studs using a vice grip and 14mm then reinstall the stud on the head without the nut. mainly the studs for each center port.

the 2 center stud holes on each exhaust manifold are smaller and the outer ones are larger. the center ones keep it lined up and make the install easier if the studs for them are in place.

I messed up one on each manifold. as I was tightening them the stud was pulling out of the head. luckily I don't hear any leaks. the pic below is the rear VQ35 manifold just to show the difference in the hole sizes.





but of course, before I was fully done it started to rain so the car is still on jack stands so I haven't test-driven it yet, only had a chance to let it idle for a few min.

uptownsamcv

I just got back from driving it around a bit, seems to pull harder above 5,000 rpm. exhaust sounds deeper and a bit louder, I think I hear some rasp but it might just be a slight rattle from my worn-out factory muffler. so far no engine light. I'm getting codes for the secondary O2 sensors mainly when I use the cruise control for a long distance. from what I see on Nisformance sight I can eliminate secondary O2 sensor codes when I get my ECU reflashed.

User1

Cool, thanks! Kept the stock muffler and resonator?

uptownsamcv

the rest of the exhaust is stock with a gutted main cat, for now. I plan to do a full 2.5" exhaust but with a chambered muffler and long resonator so it's not ridiculously loud.

i took a video, and if you notice she is still runnign strong at 301,XXX miles..

User1

Very nice! Good on you for not ricing out the exhaust. The fast and furious train left 25 years ago, it's not cool anymore. In fact, it wasn't even cool then, that's why it died.

uptownsamcv

I plan to get an 05-06 G35 sedan replacement muffler made by AP and Magnaflow glass pack for a resonator. the 05-06 G35 muffler has a 2.5" inlet and dual 2.25" outlets. I'm thinking if it flows good enough for a 298hp stock G35 sedan it should be good enough for the maxima.

User1

G's have their own unique sound/tone as well, that will be interesting.

uptownsamcv

I always noticed that about the G35's, all the parts are on the way, I'll put up a thread with pics and videos once it's all done.