New member here with '04 V8 Limited. Seeking advice on mods, please!

[4RunnerAquasport]

If your OEM exhaust manifolds are still good, that's rare any more. Most people complain of cracks and ticking, and then find there are very few solutions.

So a lot of us went w headers instead of replacing w the very expensive OEMs.
The corrosion problem was real for the early run of Doug Thorley's, especially for the. 05' and up crowd. The EGR tubes rusted quick on those guys.

They had a run of decent quality SS units, but w material shortages, I hear the wait times are pretty long.

The swap to headers is a full commitment for sure. Emission constraints aren't cheap either.

For now while your OEM manifolds are still good, you could just go with a Thorley Y-pipe (URD doesn't make one for the 03'-04') or a custom Y if you're so inclined. The factory Y borders on death by strangulation. Its just plain terrible.

Then put a larger diameter pipe between the Y and a performance muffler.
I went w one from Vibrant Performance.

This would be the most bang for buck solution and not make the emission gods angry.

 

[importman]

Just remembered something. When you get ready to replace your head unit it's the perfect time to install a backup camera. It's a little bit of a job but not too bad. It's definitely worth it to have one and since it has to connect to the head unit that's the best time to do it. Also, with the Sony unit, and I'm sure most others you should get a microphone so you can do hands free calling which is much safer and convenient. I mounted mine at the little overhead console where the sunglasses compartment is, and I've never had any problems with people being able to hear me during calls.
All this talking about mods has got me in the mood to do something else to mine. Not sure what it'll be just yet but since the bug has hit I'm sure I'll come up with something. Good luck with yours and have fun!

 

[FNG!!]

You're very welcome. The directory is here (and stuck on the top of the 4th Gen section). Also, many members link their build threads in their sigs so if you see something you like in someone's post, you can often go right to their build thread.

Another useful sticky in the 4th Gen section is the maintenance & repair writeup compilation put together by [MENTION=429038]y=mx+b[/MENTION] .

Perfect. I really appreciate everyone's help and friendly/honest input on my rather vague question. I visited a local performance garage this weekend on the recommendation from my trusted mechanic. Going to go for a Magnaflow exhaust for sure and possibly the K&N CAI for the 04 V8. The guy at the garage convinced me to skip the headers for now, as there are no issues with mine and because I didn't want to deal with the possibility of sensor alarms, etc.

Once that work is done sometime over the coming weeks, I'll turn my attention to the interior mods (LED replacements of stock bulbs, automatic map lights on when doors are open, etc.).

I also thought about looking into brakes and I keep hearing great things about the Bilstein shocks from this forum. Not sure if that applies if I'm not lifting my 4Runner and putting bigger tires, but I'll check the threads you suggest above, Bluesky.

Thanks again to all for the useful input!

 

[2003V8LTD]

I agree, except that the offset of the TRD Pro wheels is 4mm instead of the stock 20. Having the wheels 16mm outboard of where they should be, on each side, messes with the steering and suspension geometry. No way would I ever do that.

I’m new to the 4Runner world, but I will say one of my favorite mods that I’ve seen for our 4th gens is a set of TRD Pro wheel/tire take offs. It looks aftermarket, without looking aftermarket.

I’ve heard the Gibson CatBack exhaust is nice, but I’ve got no personal experience with it.

 

[FNG!!]

Excellent! Thanks for the follow up. I will check into the updates and send you a PM if any questions, just need some time to sort through stuff and make some strategic decisions on what to do when.

 

[FNG!!]

If your OEM exhaust manifolds are still good, that's rare any more. Most people complain of cracks and ticking, and then find there are very few solutions.

So a lot of us went w headers instead of replacing w the very expensive OEMs.
The corrosion problem was real for the early run of Doug Thorley's, especially for the. 05' and up crowd. The EGR tubes rusted quick on those guys.

They had a run of decent quality SS units, but w material shortages, I hear the wait times are pretty long.

The swap to headers is a full commitment for sure. Emission constraints aren't cheap either.

For now while your OEM manifolds are still good, you could just go with a Thorley Y-pipe (URD doesn't make one for the 03'-04') or a custom Y if you're so inclined. The factory Y borders on death by strangulation. Its just plain terrible.

Then put a larger diameter pipe between the Y and a performance muffler.
I went w one from Vibrant Performance.

This would be the most bang for buck solution and not make the emission gods angry.

This is awesome information, thank you so much. Exactly what I was looking for in terms of the exhaust. Good to know that the factory Y-pipe is not the most efficient, to put it lightly if I catch your context from above.

So a pretty dumb question, but I am going to ask anyway, if the headers are still good, which they seem to be, then the aftermarket Y-pipe, whether Thorley or custom, would connect from either downstream side of the headers and back towards the straight section of the exhaust (which you recommended to replace with a larger diameter pipe vs stock), then to the performance muffler (I have pretty much decided on the Magnaflow at this point). For the time being I won't cut off the resonator but instead see how it sounds as-is.

Is that description accurate? Sorry, I know it's a noob question, but I'm here to learn and appreciate your patience.

Where on the line do the O2 sensors and catalytic converters live?

Thanks in advance! Enjoyed the quip about not making the emission gods angry :becky:

 

[FNG!!]

Just remembered something. When you get ready to replace your head unit it's the perfect time to install a backup camera. It's a little bit of a job but not too bad. It's definitely worth it to have one and since it has to connect to the head unit that's the best time to do it. Also, with the Sony unit, and I'm sure most others you should get a microphone so you can do hands free calling which is much safer and convenient. I mounted mine at the little overhead console where the sunglasses compartment is, and I've never had any problems with people being able to hear me during calls.
All this talking about mods has got me in the mood to do something else to mine. Not sure what it'll be just yet but since the bug has hit I'm sure I'll come up with something. Good luck with yours and have fun!

Great points you raised about the backup camera and the microphone. I had planned to do both eventually, and good to know they play well with the Sony headunit you mentioned, so I might as well plan for all three at the same time. I will add this to my list - thanks for the update, that was very helpful!

 

[ads2539]

Re. your 1990’s tape adapter, there are gadgets now that let you send an fm signal to the radio. I used one before I upgraded my head unit to a bluetooth enabled model.

 

[4RunnerAquasport]

This is awesome information, thank you so much. Exactly what I was looking for in terms of the exhaust. Good to know that the factory Y-pipe is not the most efficient, to put it lightly if I catch your context from above.

So a pretty dumb question, but I am going to ask anyway, if the headers are still good, which they seem to be, then the aftermarket Y-pipe, whether Thorley or custom, would connect from either downstream side of the headers and back towards the straight section of the exhaust (which you recommended to replace with a larger diameter pipe vs stock), then to the performance muffler (I have pretty much decided on the Magnaflow at this point). For the time being I won't cut off the resonator but instead see how it sounds as-is.

Is that description accurate? Sorry, I know it's a noob question, but I'm here to learn and appreciate your patience.

Where on the line do the O2 sensors and catalytic converters live?

Thanks in advance! Enjoyed the quip about not making the emission gods angry :becky:

That is an accurate description. Your Catalytic converters on the V8 are attached to the factory exhaust header/manifold. So when you remove them they come out together. See: Manifold/CC pic
I actually still have these, nothing wrong with them.

I ran just the Thorley Y with the factory manifolds and an old Thrush muffler for a year and 1/2. Sounded pretty good.

Now for the o2 sensor placement. The first two in the upstream flow are NOT o2 sensors. They look almost identical, but they are air/fuel ratio sensors.
If you look at the pic of mine, you'll see a small hole on the inside of the bend. Thats where the A/F sensors live. If you go with just the Y pipe and do not replace the factory manifolds, you will not need to touch them.

Behind the catalytic converter in the down stream flow are the o2 sensors. They live in the Y pipe, and will then live in your Thorley Y pipe.

 

[FNG!!]

Re. your 1990’s tape adapter, there are gadgets now that let you send an fm signal to the radio. I used one before I upgraded my head unit to a bluetooth enabled model.

Interesting, I didn't know that but it does make sense. I will take a look into it, it's just a matter of if I want a stopgap to not deal with the excessive wires hanging out of the cassette deck until I install a new head unit. Thanks for the information!

 

[FNG!!]

That is an accurate description. Your Catalytic converters on the V8 are attached to the factory exhaust header/manifold. So when you remove them they come out together. See: Manifold/CC pic
I actually still have these, nothing wrong with them.

I ran just the Thorley Y with the factory manifolds and an old Thrush muffler for a year and 1/2. Sounded pretty good.

Now for the o2 sensor placement. The first two in the upstream flow are NOT o2 sensors. They look almost identical, but they are air/fuel ratio sensors.
If you look at the pic of mine, you'll see a small hole on the inside of the bend. Thats where the A/F sensors live. If you go with just the Y pipe and do not replace the factory manifolds, you will not need to touch them.

Behind the catalytic converter in the down stream flow are the o2 sensors. They live in the Y pipe, and will then live in your Thorley Y pipe.

Hey Aquasport, thanks a lot for the confirmation, the picture and also for that detailed summary - I'll make my own sketch based on your description; it's cool to be able to put all this information together in my head. Thanks a ton for taking the time to respond and giving me that useful information!

 

[Napalm]

I agree, except that the offset of the TRD Pro wheels is 4mm instead of the stock 20. Having the wheels 16mm outboard of where they should be, on each side, messes with the steering and suspension geometry. No way would I ever do that.

Good to know! I didn't realize that was the case.

 

[Napalm]

Not at all. Just do a search on eBay. I don't have a link handy. I can't remember exactly how much it was but it was cheaper than I expected. Like between $100 and $150 if I recall. They are aftermarket units but they look great and work just fine. You just have to find your paint code and order one with that code.

Awesome! Thank you! I'll check it out.