So 4 days ago I had a decat pipe installed. Its been fine up until today. This morning I started the car and I can hear what I assume to be an exhaust leak. Its coming from right under the car so definitely the decat pipe. Its probably just a matter of tightening the bolts up a bit more. But are there any other symptoms of a leak other than the noise? Will it affect performance or fuel efficiency in any way until I can fix it? My jack is broken right now and the mazda jack isn't high enough to get the car on jack stands so i'll just take it back to the mechanic that installed the decat next week. But is the car okay to drive in the mean time? I know rotaries can be overly sensitive to ******* everything under the sun so i'm just making sure Thanks in advance.

 

If the leak is big enough and pointed at something important (wiring, etc) then it could melt it.

Other than that, it shouldn't affect anything other than noise and, potentially, your health if you smell fumes while driving (don't breath exhaust fumes for very long).


Odds are, the heating/cooling cycles loosened up the 3 fasteners where the pipe connects to the exhaust manifold. Just put the passenger right side of the car on jack stands and get in there with a pair of wrenches to tighten them down.

 

Okay thats a relief, I thought I better check. Better safe than sorry. I don't believe there is any wiring looms next to the exhaust anyway other than maybe the oxygen sensor wire but that should be clear of it. Brake lines run down the left side of the underside. Thanks for the info, I'll get this fixed next week. But now i'm happy to drive the car in the meantime.

 

May want to check what gasket material was used at the front midpipe join (header to midpipe). If it's that aluminium paper stuff, it won't survive very long (ask how I know). Mazda uses a donut gasket in there, and the stock midpipe or the header (can't remember which, maybe both) has a recess for it. If it's leaking through that joint, just make sure the donut is in there.

 

I'll check it out as best I can later. The kit I bought included both gaskets inc the doughnut gasket. It felt pretty tough from inside the baggie it came in. Sure does luke like the ali paper though

The pipe after I wrapped it up to keep the heat in

Also I kinda expected my engine check light to come on by now because of the decat but its not.. weird

 

What you are referring to as the donut is the rear gasket. The OE front gasket is a circular gasket that fits into recesses between the pipes. The flat gasket you have there is pretty much guaranteed to leak under the temps a rotary emits.



You didn't buy the proven BHR midpipe because?

 

Here's the right gasket at Racing Beat, but your original one should still be usable if the mechanic kept it.

Exhaust Gasket - Donut Style, RX-8 Header/Race Pipe for RX8 - Racing Beat

 

In my experience, I would double check where the header/exhaust manifold connects to the mid-pipe. I had an exhaust shop do it for me, and they messed up the first time. The exhaust sounded a bit off(has a bit of that "Civic fart can" noise at certain RPM) and there was a bit of fume in the cabin. Went back to the shop and asked them to double check their work, and they indeed found a small leak between where the EM and mid-pipe meet. They redid the connection, added a bit of exhaust sealant to be safe, and I never had any problem again.

With the whole trade war deal, it probably gets really expensive to ship and import. Even when I bought it, it was expensive.

But is it worth it? In a long run, yes. It won't have its packing blown out because it doesn't have any. It also sounds really nice and gets a lot of compliments, as well as keeping the volume low when you don't need it.

With OP's pipe, I'd be curious how long the resonator lasts, especially with hard driving. As far as I am aware, BHR's resonator is exclusively sourced. Especially with the wrap, you would trap the heat in the pipe and raise the exhaust temperature even more, which is hell on the packing material.

 

Really not bothered how long the resonator lasts to be honest. If it gets a little louder over time then so be it. One day i'll change the catback anyway for something better and that will sort sound out. BHR pipe is almost $500 and my pipe is like $250. And to be fair its just a metal tube with some connectors.

 

I am not sure if it just be "a little" louder over time, otherwise BHR mid-pipe will not be nearly as popular.

We are aware of cheaper options, it's just that people haven't found one that will last a long time other than the BHR one. It's double the price, but also a "buy once, cry once" deal.

Anyway, keep us posted.

 

Except that it is more than a metal tube with some connectors. Most midpipes blow our their packing quickly. The BHR pipe uses a spiral resonator that almost never fails--even on the track. The BHR pipe also comes with a full set of the *correct* hardware and gaskets plus excellent customer service and support. Most people who don't buy the BHR first throw their money away the first time, then buy BHR the second time.