Downpipes & Best Practices

[Maximus]

Any updates here? Just curious how everything turned out. Are you guys still enjoying your setups? Im looking into exhaust/ downpipe setups now and have the same questions regarding CEL's and noise / drone, etc.

I’m enjoying my set up ??
Check engine light was gone once the car was tuned

 

[Ali023]

Welcome to the forums!

I personally went with Fast Intentions exhaust and matched it with their LOWER downpipe.
I also dont want to "be that guy" with that loud exhaust. Fast Intentions nailed it for people like us who just want deep tones. For performance, a full down pipe is recommended. If its sound you looking for, a lower downpipe would help and give performance as well ( not as much as the FDP).

LDP should not give you a CEL but will with a FDP (but a tune will fix that). Any Downpipe you put, will most likely void your warranty. It can depend on the service department really, some are ok most are not.

Labor is also a lot more for the FDP. Another option is a JB4 Piggyback tune. If any warranty work needed, you can easily detach JB4 and remove the LOWER DP much easier and make it stock much faster. Just my 2 cents.

CHEERS!

I’m on the same boat looking for a exhaust set up fbo e85 etc
Fast intention with there lower down pipes
Honestly how much hp difference between full down pipes and lower down pipes ?
my tuner said do lower down pipes because the full down pipes will make the turbos smoke and power Increase is marginal
Also if you have any video clips of your set up fi exhaust with lower down pipes

 

[Go2ZZZ]

I’m on the same boat looking for a exhaust set up fbo e85 etc
Fast intention with there lower down pipes
Honestly how much hp difference between full down pipes and lower down pipes ?
my tuner said do lower down pipes because the full down pipes will make the turbos smoke and power Increase is marginal
Also if you have any video clips of your set up fi exhaust with lower down pipes

Hey Ali! We’re in the chats on IG as well

 

[5thZ]

Just to point out a couple things, in the USA at least

Down pipes and honestly nothing, will "void your warranty" on your vehicle. There's nothing you can do that will void the entire warranty on the vehicle. That said, if you had damage to the turbos like you're worried about, it is legally required that the dealership has to *prove* the modification caused the damage, in which case your warranty will not be voided, but your warranty claim will be denied.

Next, Ecutek and CEL. Who did you use? It is my understanding that Ecutek's latest updates prevent and disable tuners from disabling the O2 related CELs. I'm curious bc once I get tuned I definitely don't want to scan codes or be annoyed seeing a cel. Pls DM me if you don't want to mention your tuner after reading what I wrote

Thanks!

 

[T3R5Z]

In response to the CEL does anyone have any hard information on this? I can't see how it would be an issue as unless you are going full catless as the O2 sensor is after the factory cat in the UDP. It doesn't know about the 2nd cat in the LDP. Therefore even running a catless LDP shouldn't throw a code.
I've emailed AMS about this.

As far as causing damage to the turbos I also can't see how this is possible as the car uses optical speed sensors and an ECU controlled electronic waste gate to finely control the turbo speed and boost pressures. This advanced design is literally there to control this issue and is quite advanced. It's not typically seen on factory cars that arnt exotics.

This would be a problem in another car that's using MAP pressure to control the waste gates which is not the case. Especially with the factory CAT in place it would be impossible for the turbo to run away.

 

[T3R5Z]

So I emailed AMS they said both their catless and high flow cat won't throw a CEL "if installed correctly" which makes sense as per what I said above. I'm gonna go catless and I'll let you'll know how it goes.

 

[Hernandooo]

So I emailed AMS they said both their catless and high flow cat won't throw a CEL "if installed correctly" which makes sense as per what I said above. I'm gonna go catless and I'll let you'll know how it goes.

I had AMS Catless before, installed correctly, still got a CEL
Now AMS catted, no CEL

 

[Hernandooo]

In response to the CEL does anyone have any hard information on this? I can't see how it would be an issue as unless you are going full catless as the O2 sensor is after the factory cat in the UDP. It doesn't know about the 2nd cat in the LDP. Therefore even running a catless LDP shouldn't throw a code.
I've emailed AMS about this.

As far as causing damage to the turbos I also can't see how this is possible as the car uses optical speed sensors and an ECU controlled electronic waste gate to finely control the turbo speed and boost pressures. This advanced design is literally there to control this issue and is quite advanced. It's not typically seen on factory cars that arnt exotics.

This would be a problem in another car that's using MAP pressure to control the waste gates which is not the case. Especially with the factory CAT in place it would be impossible for the turbo to run away.

That is why a proper tune, immediately after install is HIGHLY recommended

 

[T3R5Z]

I had AMS Catless before, installed correctly, still got a CEL
Now AMS catted, no CEL

Yeah did you get a full down pipe? Factory setup is like so.

Turbo - 02 sensor - UDP w/cat - 02 sensor - LDP w/cat.

If you replace just the LDP the car won't know. Obviously replacing the UDP even with a high flow cat could cause a CEL.

Also why would you go from catless to a cat?

*Edit - I can see from your build video you got a full DP so yes that would need a tune as you have changed the main factory cat in the UDP.

 

[Hernandooo]

Yeah did you get a full down pipe? Factory setup is like so.

Turbo - 02 sensor - UDP w/cat - 02 sensor - LDP w/cat.

If you replace just the LDP the car won't know. Obviously replacing the UDP even with a high flow cat could cause a CEL.

Also why would you go from catless to a cat?

*Edit - I can see from your build video you got a full DP so yes that would need a tune as you have changed the main factory cat in the UDP.

There is only one sensor per side and its the lower. The Upper will still do its job and wont throw CELs

I went full for both, switch over to catted to prevent 1. bad smell and 2. Rasp. The hi flow cats will perform just as good as catless

 

[thesilverbullet]

Whats your thoughts on ams full race vs full street - w/ intake, exhaust & ECUTEK. No concern with catless dp‘s other dash lights.

 

[T3R5Z]

There is only one sensor per side and its the lower. The Upper will still do its job and wont throw CELs

I went full for both, switch over to catted to prevent 1. bad smell and 2. Rasp. The hi flow cats will perform just as good as catless

Great diagram where did you get that? Whoever at Nissian designed this needs to be fired! So many different diameters of piping.

My point exactly if you don't change the factory sensors it won't throw a CEL. You shouldn't need a tune and that's verified by AMS.

That's an expensive change to make I believe they are about 2k for the full systems plug all the labour it's not easy to change the DP

 

[Hernandooo]

Whats your thoughts on ams full race vs full street - w/ intake, exhaust & ECUTEK. No concern with catless dp‘s other dash lights.

they're the same as in performance

Full race will just smell weird, be louder, and give that raspy trumpet sound, dreaded by vq owners

Full street will eliminate the odour, still maintain a high volume, no rasp, more bass, due to the hi-flow cat also acting as a resonator

 

[Hernandooo]

Great diagram where did you get that? Whoever at Nissian designed this needs to be fired! So many different diameters of piping.

My point exactly if you don't change the factory sensors it won't throw a CEL. You shouldn't need a tune and that's verified by AMS.

That's an expensive change to make I believe they are about 2k for the full systems plug all the labour it's not easy to change the DP

I'm confused as to where you're getting at. Are you going to just change the Lowers? I'd still recommend a tune even if you're changing the intake to ldp and exhaust. Unless if you're just changing the LDPs, then i dont see the point

 

[T3R5Z]

I'm confused as to where you're getting at. Are you going to just change the Lowers? I'd still recommend a tune even if you're changing the intake to ldp and exhaust. Unless if you're just changing the LDPs, then i dont see the point

Yes that's what I said from the start. Just changing the LDP and leaving the Factory UDP and cat in place should not throw a CEL.

Obviously a tune is going to get the most out of the mods but I also have a warranty I don't want to completely throw away yet.

Mostly just for sound until I decide I want to destroy my engine warranty