Help with exhaust

Hello everyone. I recently bought a 2007 Mazdaspeed 3 (Mazda 3 MPS here).
I bought the car tuned, it runs at about 315HP but I want it to be stock again.
Now there are some stage 2 parts on there paired with a tune by Dramatune, I will remove these parts and reset the tune to stock later on.
One of the stage 2 parts is a CS 3" downpipe with a high flow cat, the secondary cat is removed, this is way too loud for me so I want to install a secondary cat. My question is if this will be possible or will it cause problems since it has been tuned?

 

First things first get a new tune. Having dramatune on there and driving around is a recipe for disaster.

That said you "should" be fine adding a cat as it will just reduce airflow. The issue is normally adding parts that improve airflow and ending up in a situation that the car can't handle

Why do you want to stock out?

 

Thanks for the reply!
Are they really that bad? I have heard otherwise. Good thing I am not flooring it at all with this tune I would guess, want to keep it that way until its stock again. The reason why I want it to be stock is because this is my daily and with this tune it does like 7-10km/l while stock I could easily do 10-12, and I would say it makes the engine more reliable.

Right now it has the downpipe, CS TMIC and a CS air intake, this is why the previous owner tuned it because a tuner told him that he needed a tune for those parts since the engine didn't like it. I assume I can still use the TMIC, correct me if I'm wrong.

 

you do need a tune for those parts. you would need a tune for just the tmic also

confirm that the car has a HPFP, the only way to do this is to disassemble the pump and inspect the parts

the shitty gs mileage is due to having a shitty tune. a tune from a reputable tuner would have better gas mileage than stock with the mods you have. they are all parts which improve flow through the engine, this allows increased power and increased efficiency when tuned correctly.

check which rear motor mount you have installed. some of the aftermarket ones are pretty loud so it might not even be your exhaust that is loud.

 

Tmic is "fine" without a tune iirc, if you want to go back to stock then pull the DP / add a cat, remove the intake and uninstall the acessport and run the stock tune.

Yeah dramatune is garbage I have no idea how he has the following he does on Facebook, there's a full thread in the offtopic section detailing his shenanigans if you're interested in the read.

 

Thanks for the feedback. So if I understand correctly I have to remove the upgraded downpipe, intake and tmic, then install the old parts and upload a stock tune with something like Versatune? Or do I need to do some tests after that as well?

Maybe a stupid question but the Gen 1 Speed 3 has 1 Catalytic Converter right?

 

Do you not have the access port that put the current tune on the car?

Both Gena have one cat in the downpipe and then one immediately behind it.

See my post above that I think you may be stocking out for the wrong reasons

 

My car does not have a accessport, the car was tuned with Versatune.
Good to know it has 2, it has only 1 installed so I gotta buy a new one, luckily its the less expensive one, should explain why it is so loud I guess. I want it stock because to me that means more reliability since it has 260hp instead of 315hp, or am I completely wrong about this?
Of course I know that I shouldn't have bought this car if I cared about km/l or mpg or whatever, but since my previous car, a 2003 Mazda 2 did 13,7km/l the MPS is doing pretty well with its 10-12km/l.

 

A properly tuned car for the mods it has (hpfp internals upgraded is a must) and maintained car can be as reliable if not more than stock.

For I have similar mods to you tuned by freektune pushing similar power levels for 9 years now, car has been to the track for drag and lapping events multiple times. I keep up on maintenance if anything I do it early generally.

If you're worried about reliability, do a good service, fresh plugs, fluids, air filter, clean MAF, and get tuned by a reliable tuner: freektune or purpledrank Justin and will respectively are magicians and my car drives better than it ever did stock with my freektune. Funny enough my fuel economy also improved over stock

 

The second cat isn't making a huge difference in sound

Did you check your rear motor mount and hpfp

 

Or even exhaust leak, is the stock muffler and resonator intact? Some people cut those out and it is silly loud imo

 

That's a good point I bet the resonator has been cut out

 

I have asked the previous owner and it turns out that the resonator has indeed been removed, seems like the stock muffler is still there. Soon I will visit a mechanic many other speed 3 owners in my country recommended, he will swap it back to stock and also do the tune. The previous owner also mentioned he did something with the hpfp, will this cause issues since I have been told this is a weakpoint of the car anyway?

When all of this is done I will do some research for some minor upgrades with a proper tune since I am interested in how that works myself and have the engine and gearbox etc inspected. I will ask around for that on this forum for that again for sure.

 

Don't bother stocking out. What you need to do is:

1 Install a resonator
2 Get a proper time from freektune or purple drank

 

100% this, if you don't like it because it's too loud the resonator should fix that, PO is probably talking about hpfp internals upgrade that's a good thing.

I'd get that resonator in and see how you like the sound then go from there it'll probably be pretty tolerable, that mixed with a good tune from freektune or purpledrank will have you very reliable especially if you tell them that's what you're after

 

Intake and tmic are 100% not making the car louder

 

Hi guys excuse me for the late reply. In the meanwhile I have become addicted to the sound and power it makes and want to follow the advice you guys gave me. I will go for a retune by either Purple Drank or Freektune.

I was also wondering if I could get a new cat-back exhaust with a resonator without needing a new tune since I cannot find any stock size exhausts so figured I need to go a little bit bigger.
Thanks in advance

 

You would want a new tune. Have you ever taken the time to confiywhat parts are installed for the exhaust?

 

I definitely recommend Justin at freektune. This is solid advice. Keep the TMIC and other parts. Just fix the exhaust. You want air flow and you want it cold. All that adds up to better gas mileage on a proper tune. It will help your car not hurt it.

For the HPFP...if it is upgraded that is a good thing. Recommended but no required for stock. If you ever do plan to mod the car that is the FIRST thing you want to upgrade if it's stock.