Racingline Y-Pipe Install - Did it throw a CEL?

[1125Altima3.5]

I was going to leave this alone, but since the Degrassi crew is playing "nothing to see here", I'll elaborate on the need for gaskets in exhaust systems.

When exhaust piping heats up and cools down, it expands and contracts, putting cyclic loads on all the components in the system. The function of gaskets is to provide flexible seals that can expand and contract, keeping the piping connections airtight under cyclic thermal load.

RTV sealant is not meant to do this. It may hold for 10, 100 or 1000 cycles, but cracks will grow in the material over time and the seal will eventually be compromised. The same is true for gaskets, which is why you normally replace them whenever you break and remake hot/cold metal connections (like your oil pan drain plug). But gaskets will last a lot longer than RTV sealant.

On top of that, torqued bolts will loosen after initial tightening due to the material properties of metal. (This is a little more complicated, but you can look up the details online.) That is why owner's manuals tell you to retorque wheel lugs a few hundred miles after you change wheels. Gaskets keep the exhaust seals tight even when their connection strength weakens. I'm guessing this initial torque relaxation is what broke the connection in xxxplosive's exhaust.

Theoretically you can calculate what the required torque would be to overcome all of these effects, but judging from the Racingline responses that work was not done. (And the required torque may be greater than the max torque of the bolts depending on the material and the size of the temperature variations.)

All of this talk is a very complicated explanation of something that you learn in 10th grade auto shop: USE RUBBER GASKETS FOR METAL TO METAL CONNECTIONS. Doing this could easily make the aftermarket system as reliable as the OEM system. This isn't rocket science; it's connecting two pieces of pipe.

Maybe Racingline knew this, maybe it didn't. Purposeful or genuine ignorance doesn't really matter to me though. What killed it for me was that the first response was silence (altima/maxima tuners too busy to monitor the NICO altima thread on the y-pipe), followed by blaming the customer (you broke the O2 sensor), followed by a cute little showing of Canuck solidarity, with no discussion of the single thing that could make this problem go away - a $5 gasket. Not the most confidence-inspiring sequence.

Anyways I would recommend that anyone who did the install with RTV sealant go find a gasket and put it in the y-pipe/header connection. The part is cheap and it takes 10 minutes to fit a random gasket to the joint if you have a pencil and a pair of scissors. For me - I'm going to look elsewhere for performance parts.

[txcoupe]

This argument over nothing is the most ridiculous thing I've read in a long time.Am I the only one that pulled the crush gaskets off the flanges of the original Y-pipe? And then the next thing you might want to do is place the respective gasket (front on front, rear on rear) onto the header flange. Beacause it's a crush gasket, you should be able to line it up to the flange the way it was originally "crushed" to ensure a good seal. NOW is when you might want to use a FEW dabs of RTV to hold the gasket on the header flange. Next install all the header flange bolts & nuts, loosely, and check to make sure the crush gaskets are still being held in place with the RTV. Now tighten & torque all the bolts & nuts. Pretty f***ing simple.As far as not sending any bolts goes...PULL THE STUDS OUT OF THE ORIGINAL Y-PIPE AND GET TWO NUTS THAT ARE THE SAME THREAD SIZE.If your going to mod your car (or whatever), if don't expect to have to come up with an extra bolt or extra nut every now and then to make a mod work properly, then you don't need to be working on whatever it is your fixing to f*** up.I've put over 6,000 miles on my car since I've installed my new Y-pipe from Racingline, and there has been no CEL, no leaks, no probs at all. I'm rolling with a stock exhaust and CVT.As a matter of fact, the Y-pipe combined with the K&N typhoon intake has increased my highway MPG up to an average of 28.7 mpg. So Racingline, I thank you for producing such an excellent product that I feel is the best bang for the buck out there.

I was gonna hate on all the haters out there next, but then I'd just be coming down to your level. I'd hate to have to do that.

End of rant.

[1125Altima3.5]

If you're reusing a crush gasket (which is a bad idea - they're designed to be set once and never touched again), I would recommend you use more than a dab of RTV sealant on the connection.

But I have no idea why you would risk an exhaust leak to save $5 on an gasket.

Let us know how the system holds up after a couple of years, or a few drives through colder areas (TX is not exactly a hot-cold sort of place that would increase the risk of an exhaust leak w/ a reused gasket.)