Replacing exhaust from manifold back

Hey guys, I'm in need of replacing my exhaust from the manifold all the way back to the tailpipe. I have an 01 TRD with 290,000 on it so I'm going to have to do cats and all. Any recommendations on replacement parts and where to get them? Should I go with stock sizing or can you gain a performance increase by increasing the exhaust pipe size?

Any and all help will be greatly appreciated, Thanks!

 

yes only buy 1 cat. make sure its California legal ans install the rear o2 sensor in the same location....distance and position the old o2 sensor was at. and run a flow-master series 40 for a deep throaty sound.
buy the catalytic converter here
https://www.jegs.com/i/Magnaflow/642/53956/10002/-1

Cut the exhaust at the collector and leave attached. then weld your stick pipe and converter onto that flange an go back from there. i can weld up and custom make an exhaust within 2 hrs.
I have that same cat and a 3" pipe off the coupler flange straight back to the muffler. and then into the muffler no resonator so mine sounds mean and gnarly.

You can gain performance by using the 1 cat instead of 2 and the shorter series muffler and the larger diameter pipe because at that collector both header are shaped like 2 D's back to back creating a circle and then they go into the cats from there and straight back or up over your axle depending on the lift you have.

 

some pics to guide you. my welding isn't pretty but it works.

 

Will I still be able to pass emissions with only 1 cat? So the 1st cat off the manifold you removed completely and are only running the second?

I just called the dealership for a quick quote and they want over 4 grand for just the parts?!?! wtf?!

Thanks again for the help!

 

if you do as i said with the o2 sensor you will have no issues. mine passes every year. Do not use a rear o2 simulator if you delete the rear cat. It needs to be present so the truck can keep it self running right. it needs the rear o2 info to calibrate the fuel injection system. take old pipe off and duplicate it without the rear cat. o2 sensor same spot exactly!

 

LOL good old STEALERSHIP pricing. this should cost no more than $200.00 in parts. biggset cost if muffler, exhaust tip, and cat.

 

Do you live in California? If so, you have to keep the same # of cats the truck has stock. Technically, you can't even touch the stock cats unless they are actually bad.

 

oh ok gotcha, makes sense thanks! I guess I should add that I have had a p420 code for awhile... i've replaced the o2 sensors and the fuel filter, both turned code off for a short time then came back. I'm guessing those cats are the reason for it now. Would switching to just one cat affect this at all?

Not in California, in colorado although it's quickly becoming california with all the transplants!

Sorry for all the questions, this is my 1st tacoma and I haven't gone through replacing an exhaust before : /

 

nope i live in utah. and half the time they dont look at the cat. they just hook up obdII and scan from there....they have no need to look underneath if its working correctly.

 

just make sure that the cat is is 49 states legal. now even up here if it was going to live in CA then you may not want to do that. California emmisions is Bullshit anyways and it's way to strict and even motorcycles have to have cats down there.

 

is this the OEM exhaust you are changing? pretty decent mileage on it if it is
i am in need of replacing my original stuff from the cat back after 22yrs and less than half the miles, that nasty liquid salt they use here done taken its toll and a nice big hole on top of the muffler is getting worse and maybe loss of performance. I still haven't pulled the trigger on anything because i have no clue for after-market, my year's model OEM is discontinued but the price was like $800 or so installed (just the cat back piece) years ago when I inquired at the dealer mechanic.

I have been looking at this one from realtrucks.com



anybody using this?
million mile warranty

...

how did you know the cat was bad and needs replaced? is that what the p420 code is?

are your exhaust manifold still in good operating condition? not sure which engine you have

 

I've heard rock auto has a complete kit for tacomas.

anybody make a muffler that's as quiet as stock? i hate loud and even "throaty" mufflers on my vehicles.

 

Well I'm not positive the cats are bad but after 290,000 miles and the consistent p420 code after new o2 sensors and fuel filter i'm just guessing it's time. Plus the exhaust is starting to develop holes in the piping from rust so it seems like a good time to do the whole exhaust. The manifolds seem to be in good condition. I have a 3.4l

There's a good sticky thread at the top of this forum about the p420 code, it indicates a catalyst inefficiency problem between the 2 oxygen sensors. But this can be caused by lots of things, not just a bad cat. In fact most say it usually isn't the cat, but again after almost 300,000 on the original exhaust it seems like it definitely could be in my case.

 

California, 40 million people, Colorado, not even 5 million. But yeah, becoming more like California every day...

 

since your 're considering this and I'm in the same boat.... what's a decent aftermarket 50 state cat? i bought one from auto zone which i think was walker. i didn't like the quality. the welding had melted part of the element, the angle of the bend didn't line up with the stock pipes and i didn't like the way the bend was made. it wasn't smooth.
i return it to AutoZone and somehow made it through smog.

rock auto has the same cat but 200 cheaper than i paid at AutoZone. not a bad price of it works though.

my wife's car i took to muffler shop. they welded in a universal one for about 400 bucks when the cheapest 50 state option was 1k(it was part of the manifold). i might do that again with the truck. they can fit the cat perfectly and do it cheaply and quickly.

 

haha true! thanks for pointing out the error in my thinking and correcting me, just like a proper californian would do ; )

I'm not sure what a good 50 state cat is though, does anyone else have recommendations for brand or quality or cats for these trucks?

Also I think the stock tubing is 2 1/4", do most people go up to 2.5 when replacing the entire exhaust?

 

49 state cat is just going to have less material. if your vehicle is from Cali or is otherwise built to that standard, it may need a 50 state cat to satisfy the ecu and shut off the check engine light. just my speculation. but as more emission stations are just going by onboard emissions checks without even b measuring tailpipe emissions, the moist important thing is to shut off that light and satisfy the computer.

 

I have the JBA Stainless Steel cat back system. I sounds deep and throaty sounding.

 

Having played the custom exhaust system route for years I got tired at having to put up with discontinued parts always getting pipes bent and welding things together.

For the last 20 years I have gone with Walker Exhaust it fits .

If I need just one part it is simple to replace .

Nice and Quiet .

If you have the California Emission package no matter what state your truck lives in if you have emission inspections all the parts need to be there .

 

Does anyone have experience upgrading the piping from 2 1/4" to 2.5"? Is there a performance increase by helping it breathe or is the stock sizing preferable for backpressure?