So I got an exhuast leak that makes me sound like I am running a diesel, and I figured if I am going to pay to have that fixed, I might as well get it fixed right and put more power into the 3.0 v-6. It seems like downy headers are the way to go. Any pro's or con's? I heard installation is a @#$!$, so I am thinking of getting someone to do it for me. Has anyone paid to get this done in the bay area (CA)? What is a reasonable price? Or should I forget the headers and just get the problem fixed w/ stock parts? Thanks in advance....

~gabe

 

Try a search for Downey headers...I'm sure you will find plenty of reading material.

 

I just installed a set on my 3.0. It is a pain in the rear. Although if you have a body lift it should not be as hard to do. They sound good but I have not had a chance to drive the truck to confirm that the investment was worth it. If you decide not to do it I have the stock exhaust manifold and crossover I would be willing to sale. Good luck

 

The headers are good, but the gaskets leave something to be desired. I changed mine up to prevent leaks and so far have been successful: Cut Headers

Midiwall (if you read this), did you ever get around to getting a set for your rig?

 

Yeup... They showed up about a week ago! They're Purty!

I'm heading down to Dr. Z's this weekend to get some help with miscellaneous stuff, including some quasi-dyno work and tuning. Once I get a dyno baseline, then I'll get the headers put on and be able to compare/contrast.


WAHOOO!

 

Churnd, how wide and long are those cuts? From the photo, looks like something that could be done with an angle grinder and cutting disc, maybe a jigsaw/sawzall with a metal cutting blade???

 

Good luck with that!!

 

Think Dremel. I don't know how it would affect installing the headers if you cut the flange beforehand since mine were already welded to the exhaust pipes which supported it while the cuts were made. I don't think it would be a problem though. Actually, I'd install the headers first and wait and see if they develop leaks. That's the only reason I cut mine in the first place.

 

Okay, dumb question here. I don't know anything about headers really, so how do you know if they have a leak? Bad sound, drop in pressure, what exactly does it do that makes you know you have a leak?

 

As far as I know, you'd be listening for things to be getting loud, and the smell (or even the vision) of exhaust in the engine bay and passenger area.

There should be an air-tight seal from the throttle body to the tail pipe. A leak on the intake side will produce a whistling, a leak on the exhaust side will show you exhaust gases. Both will reduce power.

 

header leaks sound like a clicking/tapping noise that gets louder with load. with the engine idling, lightly give it gas in gear with the brake applied and it should be apparent.

creed

 

so what about ceramic vs. chrome? Obviously the ceramic will run cooler in the engine bay, but its not like I live in the desert or do extreme crawling...so I am thinking the standard chrome will work just fine. Or is it worth the extra 100 bucks for the ceramic?

 

Ceramic is the only way to go. It will also increase the life span of your headers.

 

I thought this was the sign of noisy injectors or noisy valves. This is what mine does - do you think my exhuast manifold is leaking?

 

the sound of an exhaust leak gets louder with load, whereas the injector and valve clicking stays the same intensity.

creed

 

Installed today!!

http://www.midiwall.com/4Runner/headers.html

I'm happy, but there are issues with the install... the page has details. The truck will be going back probably on Monday.

 

Hope you get that worked out. Can you notice the difference?

 

Mike, to check if it's your injectors put your finger on the fuel pressure regulator, circled in green. You'll be able to feel the ticking.

 

Ya' know... when I first drove out of the shop, I was kinda' dissapointed, but chalked it up to being an issue with the screwed up exhaust piping.

I went back out a couple of hours later and the truck seemed to be running a LOT better. I'm not sure what had changed... maybe the ECU was just happier, maybe the drop in air temp helped, dunno.

I'll be back out in a bit and have a better idea of what's what. But if it runs again like it did last night, then yeah, I'm real happy.

 

There will be a tapping that gets louder with load - as someone mentioned. There will also be a loss of power as exhaust will go "unsniffed" causing the O2 sensor signal to freak out.