New Issue.

[alhope34]

Hey guys, I'm getting a rotten egg smell from my exhaust when it is reved up. Does that mean my cats are gone?

[laksman91]

well..... the rotten egg smell is hydrogen sulfide, possibly try gas from a different gas station? If im not mistaken, Shell has high sulfur?
Could be the cats too, you do have an aftermarket DP with HFC right?

[alhope34]

I put the stock exhaust back on long ago. There's a Shell across the street from my apartment that I have gotten about 85% of my gas from since I bought the car and it has never smelled like that.

[Sean80]

My car smells when I put shell gas in it too. I've stayed with ultra 94 for the last bit, and don't get that smell anymore.

[PearlM3]

Have you thought of the obvious answer.......Maybe someone stuffed some eggs up your exhaust pipe??:pofl

[Unoriginalusername]

Hey guys, I'm getting a rotten egg smell from my exhaust when it is reved up. Does that mean my cats are gone?

that is what happens when you're cats are failing/failed. Might be able to find someone selling a stock TBE after they've put in a CPE/Cobb which would get you new gear cheaper than replacing the cat at the dealer.

With the amount of smoke the ms3 generates I am delightfully surprised to hear that the cats made it over 100,000

[alhope34]

Does anyone know if the cats would be covered under my 160k bumper to bumper? Or are they in the same class as my rear shocks and Mazda thinks they aren't between the bumpers?

Also, I don't think there is 100k kms on the cats yet. I've only used the first cat for maybe 45-50k and the second one maybe 90-95k. Will having blown out cats have any negative effect on hp/tq or fuel mileage. I obviously know it would fail an e-test but I have another 2 years before that comes up.

[WeatherB]

I'd expect it to be covered but someone with more first-hand knowledge can confirm...

Here is what I saw on Mazda's website:

Emission Defect: Only 3 components are covered: Catalytic converter, Electronic Emissions Control Unit (P.C.M) and the On Board Emissions Diagnostic Device.

[alhope34]

Nice. Maybe I can get brand new ones for "free". I should take the car in and ask sometime this week. The odour isn't TOO bad at normal idle, but if I rev the car then go to the back, it smells super bad. I first noticed a couple days ago when I was on my buddy's bike which is parked behind my car, then he started my car. Smelled so rotten. Then after a few seconds the smell went away and only came back when he reved it to 2500+ rpm. Was a hot start, btw. This actually makes sense now because on Tuesday the car threw a CEL and Thursday it went away after a few hundred km. Just like when I'd throw the odd CEL for having no cat with my turboxs downpipe.

[laksman91]

blown out cats wont decrease hp/tq. Its just useless to have that restriction without the environmental/legal benefit

[alhope34]

Well, it's not like I have much choice. I'm not going to run out and spend money I don't have on a new downpipe. I'm going to the dealer sometime this week and see what they say. If it's covered then great, I'll get new ones, if not, I might have to wait a year or so before getting stock ones again.

[Zoom Zoom Boy]

Usually happens with gas high in sulfur as someone mentioned. Esso gas has the highest concentration of sulphur and Petro Canada was next. Sunoco was the cleanest and Shell was ok. Mazda even has a TSB regarding exhaust smell with high sulfur gas.

Try filling up with a few tanks of Sunoco and see if it goes away. If it doesn't, then your cat(s) are indeed on the way out. They should be covered under the emissions portion of your warranty if they fail this early.

[alhope34]

Alright, I'll do that. The 94 they have at Petro now, is it the exact same as the 94 at Sunoco? I got a card for 5 cents off per litre for 100 litres when I switched my Sunoco points to a Petro points card.

[laksman91]

Alright, I'll do that. The 94 they have at Petro now, is it the exact same as the 94 at Sunoco? I got a card for 5 cents off per litre for 100 litres when I switched my Sunoco points to a Petro points card.

Yeah same stuff

[pacmann33]

My car smells like that after I get krowned...for obvious reasons.

[Zoom Zoom Boy]

Alright, I'll do that. The 94 they have at Petro now, is it the exact same as the 94 at Sunoco? I got a card for 5 cents off per litre for 100 litres when I switched my Sunoco points to a Petro points card.

Yup. Same stuff.

[alhope34]

Well, I'm at the end of my 2nd tank of 94. I don't smell the rotten eggs anymore. Could it have just been a bad shipment of gas my Shell got?

[Fack_Dude]

Nah, it's the cheap shit gas!!! Stick with the 94 and you will be golden....... There is way too much shit in the lower grade fuel.....

[alhope34]

Was just Shell 91...I've used it for years at the same station with no trouble before now. I'm going to try it again and see if the smell comes back. I was told by a couple people that Sunoco's 94 is artificially enhanced with more ethanol to bump up the octane rating which may not be good over time for our cars. Shell 91 is the only gas around I know of that is 100% gasoline and 0% ethanol.

[gotak]

Was just Shell 91...I've used it for years at the same station with no trouble before now. I'm going to try it again and see if the smell comes back. I was told by a couple people that Sunoco's 94 is artificially enhanced with more ethanol to bump up the octane rating which may not be good over time for our cars. Shell 91 is the only gas around I know of that is 100% gasoline and 0% ethanol.

That's one of the reason why I go to shell. Although sometimes I think maybe I shouldn't because of their bloody involvement in the ***** delta. Ethanol has less energy per volume than gasoline so without ethanol you should get fractionally better mileage.

[taz4432]

Ethanol should not cause any harm to our vehicles and as far as I know, the 94 contains no ethanol. The best bet is to call Petro Canada up and ask them.

[laksman91]

Ethanol should not cause any harm to our vehicles and as far as I know, the 94 contains no ethanol. The best bet is to call Petro Canada up and ask them.

No they for sure have ethanol in them. It says at the pumps. Shell has a "no ethanol" sign on the 91

[taz4432]

No they for sure have ethanol in them. It says at the pumps. Shell has a "no ethanol" sign on the 91

I know Shell has "No Ethanol" signs for their 91 octane but I know that in at least some provinces/locations, the 94 octane does not have ethanol. My suggestion would be to call Petro Canada and ask them. I know the sign says 'may contain up to __% ethanol' or what-not but the company only needs to have a 5% ethanol content as the average of all their products so it's very possible that the ethanol is in the 87/89/91 octane.