Header info for a newbie

[Foobar]

Originally Posted by B-R-Z

Messing with emission output at the mufflers isn't affecting anything mechanical in the motor/car itself, you are just pissing off the government. If they deny a claim for me asking them to replace my secondary cat due to the absence of the primary cat then I would agree with them. But if I threw a rod or something and they tried to deny my claim I would fight with them for solid proof that moving an o2 sensor caused it to happen.

OK then, if that's your experience great - that has not been my experience in both Illinois and New York. Other states may vary.

Anyway, I think we've thoroughly derailed the OP's original thread, and we keep going back to the warranty discussion that I thought we drove away from already

Should probably create a new thread to discuss relocation of O2 sensor.

[B-R-Z]

It hasn't been my experience, I've never done this before. I'm just speculating like the rest of the people commenting in this thread. What have you experienced in Illinois and New York related to this topic?

I think our discussion is relevant to the OPs question.

[Foobar]

Originally Posted by B-R-Z

It hasn't been my experience, I've never done this before. I'm just speculating like the rest of the people commenting in this thread. What have you experienced in Illinois and New York related to this topic?

I think our discussion is relevant to the OPs question.

OP didn't ask anything about warranty, but OK.

On a previous car with exhaust modifications that included removal of the stock cat, no problems were encountered for at least two years. Suddenly, I was getting cylinder misfire codes and when the car was brought in, the dealer took one look at the aftermarket headers and the tampered emissions system and decided right then and there that there was nothing they could do under warranty. Even after installing the stock exhaust system, the misfire was still there. Could I have pursued this further with the manufacturer and argued the whole Magnuson Moss warranty act? Possibly - would it have been worth it? I don't know. Eventually had another (non dealer) mechanic look into it and the problem was with a bad ignition wire. Could that have been caused by tampering with the emissions system? I doubt it.

[Boofneenee]

People who replace their headers and don't get a retune should review data logs. Review a log with a header/no tune to header/ w tune. Observe your AFR and tell me if you still think getting a header with no tune to support the change is a safe idea. IMO either you get a tune with your header or you don't get a header at all.

[B-R-Z]

Originally Posted by Foobar

OP didn't ask anything about warranty, but OK.

On a previous car with exhaust modifications that included removal of the stock cat, no problems were encountered for at least two years. Suddenly, I was getting cylinder misfire codes and when the car was brought in, the dealer took one look at the aftermarket headers and the tampered emissions system and decided right then and there that there was nothing they could do under warranty. Even after installing the stock exhaust system, the misfire was still there. Could I have pursued this further with the manufacturer and argued the whole Magnuson Moss warranty act? Possibly - would it have been worth it? I don't know. Eventually had another (non dealer) mechanic look into it and the problem was with a bad ignition wire. Could that have been caused by tampering with the emissions system? I doubt it.

I never said he brought up warranty but he's asking about any complications with an aftermarket header and this discussion is relevant to that, including warranty complications.

And with your issue that's your fault for accepting the dealers bail-out saying the exhaust was the cause.

@Boofneenee give us some details I'm all ears

[Foobar]

Originally Posted by B-R-Z

I never said he brought up warranty but he's asking about any complications with an aftermarket header and this discussion is relevant to that, including warranty complications.

And with your issue that's your fault for accepting the dealers bail-out saying the exhaust was the cause.

Sure, same could be said of an ECU tune warranty denial though, so we're back to where we started.

I see this discussion going nowhere, so I wish you all the best, I'll be moving on now.

[B-R-Z]

Originally Posted by Foobar

Sure, same could be said of an ECU tune warranty denial though, so we're back to where we started.

I see this discussion going nowhere, so I wish you all the best, I'll be moving on now.

ECU tune is adjusting specs of the ecu to make the motor increase power output. Moving a sensor is moving a sensor that is there to solely check for a properly functioning cat. There's more potential for disaster and angles for warranty denial with ecu tune.

We obviously have different opinions on it, so no bother in arguing any further.

[s2d4]

Opinions and facts are two different things......
You really need to do some research on this. Boofneenee is correct and there are data logs that prove it too.
The stock tune also knocks like crazy and headers only make the issue worse with lean conditions but anyway, you are right. Keep up the good work.

[B-R-Z]

You're the expert, show and explain these logs to me.

And I'm not saying that a tune can't improve performance or correct things. My argument that you are SOL if a dealer discovers a tune and you are there trying to get a blown motor fixed.

[s2d4]

I am hardly an expert, just ain't a complete noob that is all.

I'll leave your request to the real experts as I simply do not have a high enough tolerance to do so.

[Boofneenee]

A catless header without a tune is not healthy for the engine. You are realling leaning things out which increases temperatures and increases chances of knock. You can get one and avoid tuning because you want to avoid voiding your warranty or you can do what is healthy for the engine. Not to mention your car will run like shit without a tune and headers. Your choice.

BRZ their are plenty logs out there for you to review if you want to educate yourself. The best approach is to compare a solid, quality tune to one with no tune and only headers. Compare the afr's and other variables.

[Boofneenee]

And stop with the " a tune has the potential of being much more dangerous" crap. Let's assume for the sake of this annoying argument the op would be getting a quality tune from a reputable company.

[B-R-Z]

Originally Posted by Boofneenee

A catless header without a tune is not healthy for the engine. You are realling leaning things out which increases temperatures and increases chances of knock. You can get one and avoid tuning because you want to avoid voiding your warranty or you can do what is healthy for the engine. Not to mention your car will run like shit without a tune and headers. Your choice.

BRZ their are plenty logs out there for you to review if you want to educate yourself. The best approach is to compare a solid, quality tune to one with no tune and only headers. Compare the afr's and other variables.

I'd like to learn more, where can I find logs? And I've been getting great mpg and a few HP on the butt dyno since installing my header. It's not running like shit at all, I don't think so at least. Define running like shit.

Originally Posted by Boofneenee

And stop with the " a tune has the potential of being much more dangerous" crap. Let's assume for the sake of this annoying argument the op would be getting a quality tune from a reputable company.

I never said the tune would be bad and damage the motor. The fact that a tune exists\existed is what makes me nervous. Suppose I threw a rod due or something bad, related or unrelated to the tune, and the dealer reviewed the ecu counter/status/rom/whatever and discovered I flashed my ECU at one point. I'm saying that its probably easier for them to deny shit versus me moving a sensor on a front pipe.

I know, I know, I am dumb and my motor will run terrible without a tune.

[Wepeel]

Originally Posted by chimmy

What got me, is that on the factory manifold, the primary o2 is sitting in the collector getting readings from all cylinders, where as, on every aftermarket header, it sits in a runner coming off one cylinder. I don't know why its like this, or its benefit. I'm no fucking engineer, and I won't pretend to be a fucking keyboard engineer either.

I wonder about this too. Anyone have any info or explanation for this?