3rd cat delete

[chrisday1990]

Just had the third cat swapped out for a Milltek bypass on my v6 emira. Noticed a slightly deeper tone, but nowhere near the difference I expected given how restrictive that cat looks. Curious what’s everyone else’s experience after doing this mod?

 

[SenecaEmira]

The difference is mostly noticeable above 4k RPM

 

[sixtyy]

Yeah. Very noticeable for me. I also have the jb4 tune, which makes it a little louder.

 

[chrisday1990]

Yes it’s like a deeper sound… i do get the odd crack and pop now

 

[RyanGphoto]

Yes it’s like a deeper sound… i do get the odd crack and pop now

The valve controller makes a MUCH bigger difference as you can leave the valves open 100% of the time and that is where you will get the cracks an burbles.. I did both of those for a friend and the valve controller was a much bigger difference. Why not do that?

 

[Steve24]

What about people for whom the sound is not important?

I’m about to buy the cat delete as well, but I want it for the (supposed) sharper throttle response, small gain in power and less weight.

Does the cat delete actually achieve those things or is it really just something that makes the car a bit louder?

 

[Orchardbike]

It saves a couple of Kg’s. There is a small gain in power around 5-8% I believe and it’s slightly louder/deeper in sound.

 

[NicolasB]

It saves a couple of Kg’s. There is a small gain in power around 5-8% I believe and it’s slightly louder/deeper in sound.

5-8%? Maybe 5hp, but you won't feel it unless you are superhuman in your senses.

 

[Pdl2thmdl]

I don't have the valve controller installed but have the delete. sounds the same under 4k under normal driving conditions, which is what I wanted. very civil until you go above 4k and especially wide open throttle the thing screams. it makes those moments more special for me vs having it just loud all the time. I can't notice a difference in performance.

 

[allenyao09]

I agree the valve controller makes a much bigger difference in volume. The cat delete change the tone of the exhaust on higher revs.

 

[V8Dave]

Does anyone have insight on the warranty/emissions implications of this? I'm just about to get this myself. (in the USA for what it's worth)

 

[Read T]

Does anyone have insight on the warranty/emissions implications of this? I'm just about to get this myself. (in the USA for what it's worth)

It shouldn't affect what the car's computer sees as the 3rd cat is after all the oxygen sensors, so the car will not register any difference in emissions. (Though, it will in reality probably pollute a bit more). It is difficult to see anything has been done with visual inspection since the 3rd cat is hidden behind the muffler and above the under tray so would pass most annual inspections. Unsure about warranty, but it is simple enough to swap back.

 

[V8Dave]

It shouldn't affect what the car's computer sees as the 3rd cat is after all the oxygen sensors, so the car will not register any difference in emissions. (Though, it will in reality probably pollute a bit more). It is difficult to see anything has been done with visual inspection since the 3rd cat is hidden behind the muffler and above the under tray so would pass most annual inspections. Unsure about warranty, but it is simple enough to swap back.

Thanks, I figure the engine might be the most reliable part of the car so it's not a huge gamble.

 

[Thirdgen89gta]

Does anyone have insight on the warranty/emissions implications of this? I'm just about to get this myself. (in the USA for what it's worth)

You'll fail a visual, but it won't set any codes. I guess your mileage will vary depending with the dealer. I've had dealers get all "WARRANTY VOID!" with every tiny change, while others just don't care.

Had a dealer tell me that Tracking my Focus RS was an instant warranty void, even though the manual has specific recommendations for alignment and track use when it comes to service intervals. The promos for the RS when it came out had Ford touting that it could withstand 30 minute track sessions without brake fade. Which is a total lie because how long OEM brakes last depends on the driver almost as much as the conditions and track itself. Car needed better brake fluid to handle a long session, but the OEM pads were fairly solid.