C8 Vet Convertible

Hi, If ever get my HTC (still at 3000) I am interested in upgrading the exhaust so that it sounds as loud as possible, lol.
By having an after market exhaust installed does this void the warranty?.
Apologies if this has already been asked.

Sub Driver

Usually as long as it is from the cats back it will not affect the warranty. Also, no single mod will "void the warranty." Only failures related to that specific mod could be voided. For example, if you tune the engine but your radio fails, the warranty would still cover that.

thill444

As long as you don’t tune the engine you should not have an issue with an aftermarket exhaust. Obviously you lose the warranty on the OEM part you remove.

AORoads

However while the above comments have been correct in the past, if you looked at the Borla thread it might be a different story. The ME puts a lot of things in the rear, not least of which is "heat generation." To relieve that stress on the engine, the original engineers have gone to great lengths. Borla is looking at it in a similar manner while designing a new, cat-back exhaust. If whatever exhaust you put on the car causes a problem, the solution may (stress on word, "may") be on your dime. GM designed it one way; you changed it.

And yes, I do understand some who've had cooling issues with the prior gen straight from the factory with no modifications.

Uncle Pasko 73

A Camaro owner had a warranty claim for an oil pump failure denied due to having a cold air kit. So GM can deny anything they want for even seemingly benign, unrelated mods.

Will they? Who knows.

If they do you can sue them but it probably wouldn't be worth it and they know that.

Avanti

All that's true, but ultimately it is up to GM; they make the decisions since it's their warranty. I suggest you consider doing an "Advanced Search" denoting any series from at least "C5" on, and you'll find more than you ever wanted to read about mods and warranty issues. All the best.

Sir Nuke

To the OP....if you plan on modding your car in ANYWAY. and plan on taking it to your dealer, you better check to see if they are "MOD FRIENDLY" or you may find its an issue. Some dealers are, and some are not. I took my '19 Colorado in for a first "free" oil change and found a notation on the system that I had a electrical modification on my truck.....I HAD PUT A NON-STOCK HORN on my truck.....Its the very last time I will EVER use that dealer!!

On top of that.....look it up.....The Magnuson–Moss Warranty Act (P.L. 93-637) is a United States federal law (15 U.S.C. § 2301 et seq.). Enacted in 1975, the federal statute governs warranties on consumer products. ... The law was created to fix problems as a result of manufacturers using disclaimers on warranties in an unfair or misleading manner.

RapidC84B

A buddy had his snapped axle denied for having Kooks headers installed. GM flew engineers out to inspect the car. I was all set to do headers w/o tune for the looks under the glass, but I'm not risking a $15-$20K trans bill over the improved looks. Hopefully once the newness wears off they will loosen up some. That or you'll have to swap back to stock to take it in for a drive line related warranty issue.

JABCAT

This ^^^ the manufacturer has to prove that your modifications directly caused the failure you are requiring repaired under warranty. All this “ my friend’s warranty was voided because of xyz” is nonsense. Many times it’s the owner who doesn’t understand the law & the steps needed if the particular dealership service department refuses to perform the work. GM and all other vehicle manufactures hedge their bets that the owner won’t fight them on it.

GM replaced an engine in my WS6 that had longtube headers, LS6 intake manifold, aftermarket cold air intake, cat back exhaust, etc. 2 dealers refused the repair under warranty & I had to get the Attorney General’s office involved but they couldn’t prove that any of the modifications caused the oil consumption problem (known on the LS1) & had to replace the engine under warranty. It cost me a lot of frustration and my time to gather all the paperwork, receipts, etc. on my car but the end result was a new engine.

Chrysler/Jeep is notorious for trying to void the entire warranty if there are any modifications. I had 1 dealership service department flag my wife’s Wrangler has having a lift (which Jeep says voids your warranty) when it was in for a free oil change. Funny thing is her Jeep is a special edition that came with upgraded suspension, wheels & tires as part of the package - not dealer installed, factory installed. Needless to say I found another dealership to do any warranty work.


Make sure you understand the law posted above, read through the entire warranty information provided with your vehicle & find a dealership you can trust.

RapidC84B

It's not nonsense... he posts on here and can elaborate if he wishes. Axle snapped on street tires on the street launching the car. GM flew 2 engineers in to inspect the car. They refused to warranty the axle specifically due to the headers on the car. They had him at the dealership for a face to face meeting. They were going to warranty block the entire car but sent the ECM calibrations to HQ, verified they were untouched, and agreed to leave the warranty intact at that time.

Headers = more power over OEM = denied driveline warranty claim.

You're going to fight that how? He has a dyno sheet showing a 22 horse increase over stock. Pretty easy for GM to wash their hands of it. Could he spend tens of thousands fighting GM? Sure... but what's the upside?

The MM act is intended for aftermarket parts in general, not performance parts. If you add nitrous and your air conditioner breaks they can't deny warranty on the AC. If you mod the engine and the engine breaks they can easily tell you you're SOL.

JABCAT

This actually wouldn’t be that difficult to fight at all. I don’t know the car on which this occurred but let’s say it’s a LT1 car rated at 465 hp. Your friend increased hp by 22 - documented, which would be a 4.7% increase over stock. Considering not every LT1 engine makes exactly 465 hp there is a +/- margin of error between stock vehicles of the same model, year, etc.

GM certifies the vehicle components for certain power levels & because there is a margin of error in power output between vehicles of the same model/year, etc. the vehicle components would have to be certified to accommodate those differences. There is no way GM can claim the rear axle of any car is only capable of handling the advertised power output of said car & not 1 hp more. I would almost guarantee there is at least a 5% margin of error built in to the power handling capabilities of the rear axles which then considering your friend’s documented <5% increase in power would make it very difficult, if not impossible for them to claim the headers caused the axle failure.

So I would simply find out either through GM or the axle manufacturer what power levels they are rated for. I would also pull every stock Dyno post I could find (very abundant here on the forum) to show the many differences in power output numbers of the same engine & even the potential margin of error of the specific dyno that was used his car to show that <5% difference is negligible & couldn’t possibly cause the axle failure.

I’ve read a lot of your posts & you have a lot of experience racing these cars so you are very familiar with the difference tire compounds make as far as grip & thus their affect on driveline components. What if your friend simply changed to a different street tire (that was still within spec for this car) and the increased grip provided an equivalent force multiplier on the rear axle as his 22 hp gain - would you say they can refuse to fix the axle under those circumstances?

RapidC84B

Brand new C8, snapped OEM axle, GM blocked his entire warranty until they confirmed OEM calibrations, denied the axle claim due to the headers specifically. Thew sent 2 engineers out and had video phone conferences regarding the car. $800 repair bill for new axle or thousands with an attorney trying to prove that the headers didn't take the car out of the OEM acceptable range?

What happens when you're one of the ones with a freak DCT issue... you pull in and they tell you the $20K DCT installed isn't covered because you modified the engine to make more power?

Uncle Pasko 73

You are correct; it would be easy to fight.

But it would be almost impossible to win.

JABCAT

So C8 rated at 495hp, his 22hp gain (if it really was 22hp based on dyno, margin of error, etc. ) is only a 4.4% increase over stock. Again that’s assuming his car dynoed 495 and then 517 after header install under the same conditions, correction factors, etc.

I’d be asking GM for all the documentation I stated above. It wouldn’t cost me anything in attorney fees. GM would have show that the axles can not handle a power output difference of less than 4.5% of what they rated the engine at.

The burden is on GM to prove the headers caused the axles to fail not on me to prove they didn’t.

RapidC84B

And you think GM would provide that without an attorney's letter? GM tells dealer they're not getting reimbursed for the work. Your car is inoperable... you're at their mercy. You can fix your car then spend your time and money trying to get reimbursed with little chance of doing so. Again.... you mod the car, you break the car, GM can wash their hands of the driveline.

Vetteman Jack

Putting a cat back on the car should be OK, but as was mentioned, check with your dealer to see if they would have a problem with it should you need warranty work.

Michael T*

To me it is just not worth the potential headaches. To extract the last few percent of performance and jeopardize the warranty is nota good idea. While I have read about those that have got attorneys involved and prevailed, good luck recovering attorney fees.

Shokosugi

Not directly on point for this thread but I liked this video...

AORoads

^^ And that IS the video I was referring to. Note his discussion of what insulation needs to be carefully looked at, and the amount of insulation on the stock muffler and the entire rear area.