Tune a must for lower downpipes?

[KelvinllMelvin]

Been contemplating about getting lower downpipes installed but troubled since many users says a tune is a must but don’t want to void warranty. However others are saying a piggyback like a jb4 is more than fine since i can log and choose different maps to lower turbo rpm. Primarily looking for improved sound by getting lower downpipes not necessarily chasing for hp numbers.
Note I have awe catback on with stock intakes.
Any insights on this setup?

From what I understand is the vr30 has 4 cats and the primary cat is on the upper cat. And there is a o2 sensor on the lower cat but it sits right before the lower cat but after the primary. So that tells me most of the filtering is already done through the upper cat and running a jb4 with a map setting should be fine?

 

[KrackaC8]

I'd also consider intakes for a nicely balanced sound profile from both ends of the engine.

LDPs will not throw a code since the 400-cell secondary cats are not monitored. The UDPs contain monitored 600-cell primary cats.

A tune also doesn't seem to be required (although always beneficial to maximize power). @Tranzor Z is running his with a Stillen TruControl and has confirmed his boost psi and turbo speeds are both perfect.

 

[FSUZ33]

To clarify/confirm (for my curiosity):

LDP’s, whether ‘sport’ (larger piping and/or more open cat matrix) or ‘race’ (no cat matrix) are OK without a tune?…assuming you’re running OEM UDP’s?

if so, also with aftermarket exhaust?

 

[KrackaC8]

To clarify/confirm (for my curiosity):

LDP’s, whether ‘sport’ (larger piping and/or more open cat matrix) or ‘race’ (no cat matrix) are OK without a tune?…assuming you’re running OEM UDP’s?

if so, also with aftermarket exhaust?

Yes & yes

 

[FatRatZ]

The major majority of users state that lower down pipes will not throw a code. That seems to be the case in most instances however, I just took off a set of ISR hi flow cat LDP’s this weekend because they continually throw a code for the second O2 sensor.
I have an AWE touring exhaust setup that I’m removing as well. I’ve cleared the code a bunch of times and it keeps coming back. Additionally, some emissions related codes are permanently stored so when they get to the dealer, they can see that it had been thrown. I had the permanent code cleared - this requires a plug-in consult at a dealer- and driving away from the dealer the CEL came back on. Hence, the stock lower down pipes went back on yesterday.
You are correct that it sounds a lot better without LDPs, but to me the annoyance of the CEL is not worth it.
I also had at one point, after I had already seen trouble codes from the O2 sensor , added the Stillen piggyback tuner. It gave me an over speed CEL on the turbo.
I didn’t see a huge difference with the piggyback so I removed it. After removing it, I took it back to the dealer. I work for NNA so they’re pretty accommodating and cleared all the permanent and other codes. Once again, with just the lower down pipes and nothing else, the O2 sensor code appeared on the drive home.

 

[Tranzor Z]

The major majority of users state that lower down pipes will not throw a code. That seems to be the case in most instances however, I just took off a set of ISR hi flow cat LDP’s this weekend because they continually throw a code for the second O2 sensor.
I have an AWE touring exhaust setup that I’m removing as well. I’ve cleared the code a bunch of times and it keeps coming back. Additionally, some emissions related codes are permanently stored so when they get to the dealer, they can see that it had been thrown. I had the permanent code cleared - this requires a plug-in consult at a dealer- and driving away from the dealer the CEL came back on. Hence, the stock lower down pipes went back on yesterday.
You are correct that it sounds a lot better without LDPs, but to me the annoyance of the CEL is not worth it.
I also had at one point, after I had already seen trouble codes from the O2 sensor , added the Stillen piggyback tuner. It gave me an over speed CEL on the turbo.
I didn’t see a huge difference with the piggyback so I removed it. After removing it, I took it back to the dealer. I work for NNA so they’re pretty accommodating and cleared all the permanent and other codes. Once again, with just the lower down pipes and nothing else, the O2 sensor code appeared on the drive home.

How did you not see a difference with your Trucontrol? It's literally night and day.

 

[Tranzor Z]

I'm running Stillens trucontrol, Z1 drop in filters, Catless LDPs, and Stillen competition exhaust. Would I be faster with a Dyno tune? Yes! Is it worth the money for a few HP? NAH!

 

[traska_rz34]

I'm still very curious about B6A's full 4" downpipes with the catted O2 sensors...

 

[Rzko]

I have Fast Intentions LDP and catback and have no codes and have no issues with no tune. I do plan on getting a tune at some point but has been so far so good. I will say its not as "loud" as i thought it would be which I am happy about but does open up the sound of the exhaust quite a bit.

 

[NightShade]

The major majority of users state that lower down pipes will not throw a code. That seems to be the case in most instances however, I just took off a set of ISR hi flow cat LDP’s this weekend because they continually throw a code for the second O2 sensor.
I have an AWE touring exhaust setup that I’m removing as well. I’ve cleared the code a bunch of times and it keeps coming back. Additionally, some emissions related codes are permanently stored so when they get to the dealer, they can see that it had been thrown. I had the permanent code cleared - this requires a plug-in consult at a dealer- and driving away from the dealer the CEL came back on. Hence, the stock lower down pipes went back on yesterday.
You are correct that it sounds a lot better without LDPs, but to me the annoyance of the CEL is not worth it.
I also had at one point, after I had already seen trouble codes from the O2 sensor , added the Stillen piggyback tuner. It gave me an over speed CEL on the turbo.
I didn’t see a huge difference with the piggyback so I removed it. After removing it, I took it back to the dealer. I work for NNA so they’re pretty accommodating and cleared all the permanent and other codes. Once again, with just the lower down pipes and nothing else, the O2 sensor code appeared on the drive home.

Why are you removing the AWE exhaust?

 

[FatRatZ]

I removed the ISR lower downpipe / high flow cats. I left the AWE touring pipe on the car. While I’m not a fan of its fit, it bangs and rattles against the lower x-brace, and the exhaust tip is constantly off center of the bumper cut out on the driver side rear, it does sound the best without any annoying drone imo.
Since putting the stock cats back on I haven’t had any CELs. I had tried O2 spacers and had no luck. The ISR LDP’s constantly threw check engine lights.

To be fair, it may have been the combination of the still in true control with the LDP‘s. Can’t really say for sure. I think others have had no trouble with the LDP removal. I still have the true control installed, and it doesn’t seem to have any problem or throw any check engine lights by itself.

So it’s possible the combination of the AWE pipe, ISR LDP, and true control added up to a check engine light. But it was constantly getting O2 sensor error errors.

Other than the sound, you really can’t tell a difference with the LDP’s in or out so it wasn’t worth the headache of check engine lights. Yes, I recognize you can do more with them out - however having raced many different kinds of vehicles over 25 years I can say that just that change alone wasn’t worth the headache.

 

[jacksonmagnet]

 

[Nis Mo Z]

I removed the ISR lower downpipe / high flow cats. I left the AWE touring pipe on the car. While I’m not a fan of its fit, it bangs and rattles against the lower x-brace, and the exhaust tip is constantly off center of the bumper cut out on the driver side rear, it does sound the best without any annoying drone imo.
Since putting the stock cats back on I haven’t had any CELs. I had tried O2 spacers and had no luck. The ISR LDP’s constantly threw check engine lights.

To be fair, it may have been the combination of the still in true control with the LDP‘s. Can’t really say for sure. I think others have had no trouble with the LDP removal. I still have the true control installed, and it doesn’t seem to have any problem or throw any check engine lights by itself.

So it’s possible the combination of the AWE pipe, ISR LDP, and true control added up to a check engine light. But it was constantly getting O2 sensor error errors.

Other than the sound, you really can’t tell a difference with the LDP’s in or out so it wasn’t worth the headache of check engine lights. Yes, I recognize you can do more with them out - however having raced many different kinds of vehicles over 25 years I can say that just that change alone wasn’t worth the headache.

What is your TruControl set to map wise? I think Map 7 might be dangerous with your exhaust mods(large sums of overboost) hence why I utilize Map 3/4 with my B6A intakes and Stillen Competition exhaust,

 

[thesilverbullet]

Untuned and running 3” race lowers mated to a 3” exhaust w\ nismo intake. No power loss but this setup needs a tune for sure. Some gains but not that impressive. No issues with codes..

 

[okwhateverhi]

I removed the ISR lower downpipe / high flow cats. I left the AWE touring pipe on the car. While I’m not a fan of its fit, it bangs and rattles against the lower x-brace, and the exhaust tip is constantly off center of the bumper cut out on the driver side rear, it does sound the best without any annoying drone imo.
Since putting the stock cats back on I haven’t had any CELs. I had tried O2 spacers and had no luck. The ISR LDP’s constantly threw check engine lights.

To be fair, it may have been the combination of the still in true control with the LDP‘s. Can’t really say for sure. I think others have had no trouble with the LDP removal. I still have the true control installed, and it doesn’t seem to have any problem or throw any check engine lights by itself.

So it’s possible the combination of the AWE pipe, ISR LDP, and true control added up to a check engine light. But it was constantly getting O2 sensor error errors.

Other than the sound, you really can’t tell a difference with the LDP’s in or out so it wasn’t worth the headache of check engine lights. Yes, I recognize you can do more with them out - however having raced many different kinds of vehicles over 25 years I can say that just that change alone wasn’t worth the headache.