I installed a set of Downey headers on my 3.0 pickup about a year ago, and the horribly rigged muffler set up I have is getting old. The Downey kit has a crossover that bends under the transmission and collects into a y-pipe near where the stock catalytic convertor was. The pipes in between the headers and y-pipe are 2 inch diameter, and the y pipe is (2)2inch to 2.5 inch, which stretches 20~ inches to the O2 sensor pipe, followed by another 1.5 feet to the muffler. I understand that 2.25 is the optimal size for the 3.0, but I don't understand if that size is of the pipe immediately following the headers to the exhaust tip, or if only the size following the muffler, before the muffler, etc, etc. I'd like to maintain the pipes I already have ($$$), but if the Yota gods dictate 2.25 pipes everywhere possible, I'll do that instead.

To clarify, my stock muffler isn't much more than a holy can, and that'll be replaced as well.


What say you, 3vze owners?

 

I dont have answers for you, though I kinda need them myself.

really writing to ask if you have any good pictures of the exhaust set-up.

I have a set of Downeys laying around and I'm planning on installing them sometime this month. They're missing all parts except the headers and some uninspiring chrome gasket/heat shield things.

Since you installed yours long after Downey went under, did you have to jury-rig anything?

Did a shop fab-up the crossover?

edit: let me know what you decide on for a muffler (mine's about shot, too). I'm trying to stay very cheap, here, and dont really want my truck to sound like a Chevy or a Civic

 

I bought a full kit including the crossover, y pipe, and about 1.5 feet of down pipe that would connect to the catalytic converter in a stock setting. The headers themselves are good quality, but may require some work. The mounting holes on mine were inconsistently sized, but a quick visit to a drill press fixed that. When I replaced mine, I eliminated the EGR and most of the smog equipment on the passenger side, so that simplified my install greatly.

When you install the headers, make sure you steel tie your gas and brake lines at least a couple inches from the header surface, as numerous guys have roasted their trucks with inadequate spacing. I pulled the gas lines completely off the truck, recent them around the problem areas, and it's worked flawlessly for a year now. In addition to that, invest in $30 worth of header wraps for those tight spaces..because you just can't be too sure.

I'll get pics of the rigged system shortly.

 

Thanks!

Unfortunately, I don't see anyway that I can avoid dealing with all of the emissions stuff. Haven't even looked at the PAIR...ever, really. Oh well, it's not like anything in this engine bay is ever easy.

 

[QUOTE="dromomaniac;52202060"]Thanks! Unfortunately, I don't see anyway that I can avoid dealing with all of the emissions stuff. Haven't even looked at the PAIR...ever, really. Oh well, it's not like anything in this engine bay is ever easy.[/QUOTE

If you're area doesn't require any emissions testing, rip that crap out of there! If it does.. Just buy some stainless steel flex pipe that'll run from headers to PAIR/EGR.

 

Don't mind the messy truck.. These pics were all pre-cleanup:




The pics should explain themselves, but the last pic shows the 2.5 in y pipe end before the stock location of the catalytic convertor, which I removed. This resulted in a very bootyjank setup, indeed.

This was all in a kit from the Downey factory, so any questions regarding specifics, I probably can't answer, but I can help whenever I get around to installing a new muffler!

EDIT: Chances are, I'll end up going with a 2.5 in and out muffler to reduce the amount of work needed, as well as remain valid whenever the 3.4 indubitably comes around!