When Jay Emm visited America two years ago, he stopped here in Nashville and we put him up. We took my car down the Nachez Trace where he had an opportunity to wring it out. He commented to me how much quieter my car was than his even when used in anger.

We quickly surmised that was due to the addition of the third cat which they don't get in Europe. As BJBJ says, our cars are delivered with that third cat, a feature the European cars do without. So there!

 

Just do it, people. The car sounds so much better (yet is still whisper quiet with the valve closed), the engine response is improved, and you drop a little weight off the back of the car. I cannot imagine anyone being uphappy with the modification.

 

The only reason not to ditch the 3rd cat is California CARB, or if you are installing headers, in which case the 1st/2nd cats are deleted and the 3rd with modification to accept the O2 sensors is needed to be a steward of our air.

 

Julian's comment begs the question: how much negative effect does removing the third cat cause vis a vis emissions compared to retaining it? Probably a hard one to answer.

 

Well, I'm in CA, and haven't had a 3rd cat since I bought the car. I've passed 2 smog tests so far, with values nowhere close to the limits. The great thing is most shops have zero clue as to how many cats the car is supposed to have, so it passes visual and emissions based on the 2 primaries. Of course YMMV depending on your state's smog laws, testing procedures, etc etc.

 

^Good to know. I guess I'll find out for myself this year when I re-register my car. TN does annual inspections, not that we have particularly clean vehicles here. Rolling coal anybody?

 

Just joined the club...

 

Just got done with mine. Very nice difference in sound. Dropped the whole exhaust and used expander from O'Reilly's. This was my very first time working on a Lotus as I just got my Evora 400. Total time was 1 hour and 20 minutes. Took a few love taps with the rubber mallet. I used ramps.

 

Just dropped off my '19 Evora 400 (2500 miles) for some more warranty work. While there I inquired about if a decat pipe would effect warranty. The response was, "it wouldn't effect the warranty on say the electric windows but would void it on engine work because it changes back pressure". That euro models with identical motors don't have the cat didn't change the service managers thinking. He also mentioned a K&N filter would have similar effects on warranty. As this is my local service center, I'll have to postpone installation of the decat for a couple more years. I would expect this type of response from a Mercedes dealer perhaps but considering this car is covered for non-competition track use it comes off as a bit of a con. They also mentioned they won't do anything about the frame vibration that occurs at speeds over 90mph; essentially half speed. They said to bring it to a speed shop where I'll have to pay out.

 

'
I didn't think we actual got '19 model, jumping from '18 to '20 in US market. They will not warranty because in US "warranty" also means responsibly of vehicle being able to pass US emissions testing in any state. I would push harder on your frame vibration, whatever you are meaning by that ? a rattle or a rub?? you can escalate a warranty beyond a dealers opinion.

 

The dealer that installed my decat said they loved it so much they would recommend it to all new owners. Though it’s possible, I can’t imagine them doing that if they thought it would void the warranty on the motor. Also, I thought in the US the manufacturer had to be able to prove that the modification caused the fault to void a warranty.

Although car enthusiasts commonly believe that any modifications will void a warranty, the truth is a little less straightforward. In fact, a modification won’t void a warranty unless an automaker or a dealer can prove that an aftermarket part caused the need for repairs. In other words, your warranty will still be valid when your radiator springs a leak, even if you’ve added an aftermarket exhaust.

Autotrader - page unavailable

 

The nearest Lotus dealer is 3.5 hours away from me, and this is not that unusual for other parts of the country either. Lotus' warranty is a bit of a joke anyway.

 

Sounds like you need to find another dealership to work with. No reason a cat or air filter would void a warranty, one would think less back pressure & less heat in the engine bay is usually a good thing

for the dealer to also not want to look at the vibrations issue...

seems like the dealership doesn’t really want any return business/customers etc.

a dealer I have talked with encourages the decat over the Ti exhaust on a new GT, quite a bit less money and suppose to be similar sound.

also as mentioned, I do not believe there is a 2019 400 here in the states, the 400’s last year was 2018 with the GT starting in 2020.

 

Sounds like you need to find another dealership to work with. No reason a cat or air filter would void a warranty, one would think less back pressure & less heat in the engine bay is usually a good thing

for the dealer to also not want to look at the vibrations issue...

seems like the dealership doesn’t really want any return business/customers etc.

a dealer I have talked with encourages the decat over the Ti exhaust on a new GT, quite a bit less money and suppose to be similar sound.

also as mentioned, I do not believe there is a 2019 400 here in the states, the 400’s last year was 2018 with the GT starting in 2020.

By inception date I meant original sale date in 2/19

 

I am in the process of purchasing an Evora 400 (from a forum member) that had the decat installed. I’m extremely excited to hear the car but in the back of my head I am worried about passing smog since I’m in CA.

-Any 400 owners in CA have the decat and pass smog?
- For those that have the 3rd cat laying around since installing the decat willing to sell it to me? I would like to be ready, just in case.

 

I'm sure others will chime in, but the 2 cats in the headers are the primaries, and the 3rd cat basically does nothing. I've passed smog three times now over the past ~4.5 years in my S1 with no 3rd cat. The motor is the same, just sans supercharger.

The only time I would think the 3rd cat might come into play is if the vehicle is running so poorly that it's borderline failing emissions. But I'd imagine if that were the case, you'd fail on the MIL being lit up first. And you shouldn't worry about failing visual either; the undertray obscures the view of the 3rd cat location and test-only shops aren't allowed to uninstall anything.

 

With the A132S0230F Lotus part, do you need that wide clamp to replace the skinny one? Where can you source that? LotusPartsOnline doesn't show a part number for it.

 

If I understand your question correctly, the answer is that you use the existing hardware without additions. The stock clamp works fine to tie the thing back together.

 

OK, thanks. I read earlier in this thread that you needed a wider clamp up front.

 

It's a relatively easy job that requires you lift the car so you have some working room. The hardest part for me was getting the cat off of the exhaust plumbing which took some convincing with a soft blow hammer. You will also need a pipe expander to fit the new tube. I was able to do it myself though a third hand can be useful when reinstalling the muffler assembly back on the car.

Some people have been able to keep the muffler assembly in place but I was unable to do that as I needed to take the whole thing off for disassembly due to the reluctance of the cat to come off without convincing via the hammer. I found it easiest to drop the whole assembly, muffler, fittings and all, so it could be worked on without interference.

 

Some people have been able to keep the muffler assembly in place but I was unable to do that as I needed to take the whole thing off for disassembly due to the reluctance of the cat to come off without convincing via the hammer. I found it easiest to drop the whole assembly, muffler, fittings and all, so it could be worked on without interference.

I believe my local dealer takes off the whole exhaust to do the decat swap.

 

I've turned a few wrenches in my time. Don't have a muffler pipe expander. That may be my excuse to finally buy one of those. I've had my eye on one on amazon for a while.

 

You don't really need a pipe expander for this job, just a piece of 2x4, a rubber mallet, and take your time.

 

OK, I'll hold off on the expander. I have a 2x4 and a rubber mallet, AKA "The Lotus Wrench." Not to be confused with the BFH that is "The Harley Wrench," AKA "Thor."

I gotta go through this thread, but what needs expanding, just stick the 2x4 in at an angle and whap it to bend it out some?

 

IME, nothing needs expanding, shoot some liquid wrench in there if necessary, and use the tools mentioned. It's not a super complex system, very small as the engine is right there. I pulled out the collector as some others mentioned, since the unit is kind of heavy. Put it on a towel, do work, reinstall. Hardest part is fiddling with the rear diffuser.

 

Thanks, guys. When it gets here, I'll start digging into it. The roads still have left over salt on them. Don't care to take it out on that anyway.

Y'all have heard of the Harley took kit, right? 6 different sized hammers? Pretty much a "classic" Harley tool kit. Not so much for the Evo and Twinkie bikes.

 

I got my decat pipe for my 17/400 from Greg's Racing Parts a couple weeks ago - have been working on other projects and it's still sitting in the box - but appreciate you boys bumping this thread for any hints I can pick up.

Kevin

PS - I own numerous Harleys, so have a large collection of hammers at my disposal!

 

Excellent, Kev.

I have a 86 FLHT that I bought new (I opened the box it came in,) a 87 XLH that I bought new for my wife while on a road trip in Canada. She rode it home to Central Texas by way of Los Angeles. Wore out the chain and rear tire before we got home from the dealer. And a 99 crate motor Evo chopper, 6" over, 4" stretch. Fortunately, I no longer have a 79 FLH POS or a 75 XLH. So, I, too, have a good hammer collection in my tool box drawer labeled "Harley Wrenches."

 

For the record, those $20 Amazon expanders are garbage. I ordered one specifically for the job but it broke before the pipe budged. I needed one to get the thing to slide on but not everybody does apparently. In the end I borrowed a set from Auto Zone on their loaner program. It was a real tool that saw the job done. I would expect to have to employ some form of persuasion as mine required it. I didn't imagine that! If you are comfortable improvising, great but if your car is like mine, you'll have to expand the tube to get the fitment established.

 

For the record, those $20 Amazon expanders are garbage. I ordered one specifically for the job but it broke before the pipe budged. I needed one to get the thing to slide on but not everybody does apparently. In the end I borrowed a set from Auto Zone on their loaner program. It was a real tool that saw the job done. I would expect it to have to employ some form of persuasion as mine required it. I didn't imagine that! If you are comfortable improvising, great but if your car is like mine, you'll have to expand the tube to get the fitment established.

The ones from Hazard Fraught are no better...

 

I borrowed mine from Advanced Auto Parts. Broke one of the spines and quietly returned it.

 

I have the HF set, and it is useless as an expander. Works to make things round again and that's about it. Put enough torque on it and it will strip out way before it expands anything. I think HF sells it not as an expander but a "make round again-er." I was looking at a manual real set in the $150 price range. Got a link here somewhere if I can find it. I think it was on amazon.