skipjakk

Love my 2003 4runner, except for the annoying exaust sound that it makes as you step on the gas; the result of the thin headers. was wondering if anyone has heard if TRD or anyone else is coming out with replacement headers for the 2003-2004 4runner, and when?

Biff

Headers are no where in sight. Nobody has any plans to even attempt a set of headers.

doanlaw

Well JBL wants my new rig to demo thier header/exhaust system. In exchange I get to keep the system. Hmmm.....not sure if I want the new runner on a dyno at WOT with only 190 miles on it

Biff

Cool, what kind of headers are they. I've never heard of a company making headers for the 4th gen. I know there are a few exhaust systems out there. I would love to see some pics

Dr. Zhivago

You mean JBA, right?

G

Good Times

I'd be very interested in seeing how they make those headers.

The problem that I see is that the two cats are only about 18" away from the exhaust manifold making it very difficult to make headers that actually work. Since you really can't move the location of the cat w/o getting carb approval (which is $$$ for the mfg) it would be interesting none the less.

When Downey had my truck working on the suspension, they took a deep look at the engine to see what they can do w/ the headers. They initally figured they'd be able to use the tundra headers but quickly realized that the headers itself flared in the opposite direction compared to the tundra. they also noticed that the cats were alot closer to the exhaust manifold so they just said forget it. Even if you did get some kind of headers in there, the cats would be soo restrictive that you won't see much improvement... I was abit bummed w/ their answer so I took a look myself and noticed it as well...

o well.... still I'd like to see what jba does along w/ their output curves. I can be certain they can build a cat back exhaust but headers would be a daunting task.

doanlaw

YEP. JBA. L and A are on completely opposite sides of the keyboard, don't know how that one happened...

Duc Hunter

I have not looked and may be a little jaded after doing the exhaust on my VR-4 but............. why not make a header that goes from the engine to the cat and bolts onto the stock cat. This should give a nice improvement over stock. It is true that a free flowing cat or no cat would make a HUGE difference relative to the stock cats. I know I could find a shop that would install for me free flow cats or just make me bolt-in cat eliminators. Then all I would need to do is bolt in the stock cats for a smog check. Maybe I am missing something here (light that the computer, some how, could tell you had no cats and would light up like a Christmas tree) but this seems very doable to me?

Good Times

Try looking at the location of the header and cat and think again.... it's a pita!

Also then the aftermarket headers will only be 12" long thus not helping much as the stock cats are way too restrictive to begin with. I'm still curious though but don't feel too confident yet on this area.

toyota03

please let me know if they ever come out with one. That sound bothers me alot during a warm day.

EDGE

Dude has to be driving a V6, the V8 sounds awesome and you need to get on it to hear it roar

If the cats are so restrictive what about less restrictive cats

Sil23

[QUOTE=EDGE]Dude has to be driving a V6, the V8 sounds awesome and you need to get on it to hear it roar

Yes it's the V6..The sound annoys me also..other than that I love it..

scharged03

OK, what is everyone talking about? Skipjakk, are you talking about the stock exhaust manifold or headers you put on yourself? The 4th gen have TRD headers avail in V6 and V8 engine types, they're essentially Borla headers. Do a search on ebay.

I imagine stock manifolds are iron and were chosen to reduce the engine exhaust sound. Aftermarket headers are thinner and are thus louder. If the stock manifold is too loud, I guess you can wrap them them up in some heat shielding wrap.

Pitchar

Good Times

i highly doubt those headers are for the 4th gen. And if so, I'd like to see em in person because I really doubt it...

Prob someone just trying to scam someone!

SD4Runner

I still want to know what the annoying sound is? I don't hear anything abnormal on my V6, when I get on it... it sounds pretty pissed.

Sil23

I am a novice when it comes to these sort of things BUT what are the advantage and disadvantage of using this product...I also want to eliminate the noise I get similar to yours..
http://shop.ivalueinternet.com/bigex...ct_id/1131.htm

Victor

Didn't someone post that Toyota was going to change the manifold design on the V6 due to the noise complaints? Also, there is not going to be a recall for the earlier vehicles that suffer that problem.

scharged03

Sil23

The exhaust wrap keeps the heat in the headers, this keeps the engine compartment cooler but it also keeps the exhaust gases hotter, thus, flowing faster, increasing the scavenging effect. I suggested it in my previous post because it might keep the exhaust noise down on the "thin" headers.

Pitchar

PistonSlap

I think you are right. It is probably those idiots on ebay that continually post crap for 96-03 4runners when they should post for 96-02 4runners. I can't figure out why they do it because when you ask them if it will really fit a 03 they always say no.