Logged about 12k miles and keep it garaged- Regardless as winter set in a few months ago I get a nasty odor comimg from the exhaust during warm-up- like enamel - but clear , no codes , and after warm up - the smell stops- my guess is it the Cat Converter thats adaping the intake while cold - temp is usually just above freezing - no smell under the hood - asked dealer and they said the same - as well there enough codes connected to the cat / exhaust that there would be something lit up -anyone else ? thnx

 

During warm up the fueling is richer.... sounds normal to me. The HO2 (commonly miss called O2 sensors) is in open loop for 1-3 minute during that time the exhaust is warmed the HO2 then go into open loop. The coolant is not warmed for several more minutes or until it reaches 129,9 . At that time the CAT ,the coolant and your fueling are normal operating conditions. In extremely cold temperatures all of these start up condition can increase up to 5 minutes or more. You should also notice that the engine cold starting will sound much loader for the first 1-3 minutes as well.

 

Just my 2¢ but you could try another brand of gasoline. I've known that can help some.
Also, an "Italian Tune-up" might also work. That heats up the cat more than short trips and burn
off any carbon, etc.. in the exhaust system.

 

Not likely changing gasoline "brand" is going to change the smell.... from the information the OP posted .

DONT DO *THE ITALIN TUNE UP......
This is really a sure way of causing problems. Tthe OP has 12k on his new Mazda engine not yet even fully broken in yet.
*It is the lazy way of really only partially cleaning spark plugs while in the engine. It will not clean carbon off this model Mazda engine with only 12k miles....and more likely should large pieces of carbon if there were any on an engine like this with 3x as many miles or more, "BREAK" free will get lodge in areas of the exhaust system that will create problems.

The operation of a catalytic converter is obviously not completely understood.




ASE

 

To expand: Different brands of gasoline can have different or differing amounts of additives. In addition, different
grades of gas also can have differing amounts of additives. Premium grade, none gasohol, can clear up the fuel system to
some degree and also the exhaust system.
As far as an 'Italian tune-up', I'm not talking a 6000 rpm, 10 mile run. While that could work, I'm referring to a warmed up engine,
aggressive acceleration and a high speed run, say 70 mph for several miles.
At 12,000 miles, the initial break in should be complete. There is a second phase were the engine seems to 'free up' a bit more.
That is often around 25,000 miles from my experiences and others I know.
Your choice of course,
My 2¢

 

Dennis he said it cleared up when the engine was warmed. Re-read the first post again! So gas brand has nothing to do with his question!
As for you armchair comment of retail gas formulas ...better do some serious research and learn how that really works and not guessing or reading a few internet info on the subject. You need to go directly to the petroleum facilities that mix the formulas for the different brand fuels. Good luck getting them to release the formula information. LOL We did this years ago before California change everything for most every state having to do with emission and fuel formulas.

And NO you don't aggressively throttle a Mazda Skyactiv engine up as you described until the engine has been completely broken in. I will refer you to the type of rings used the material of the pistons and the finish hone in the cylinder's

There is no such thing as initial break in and at 12k miles most Mazda engines are not broke in. I refer you to scoping Mazda Skyactiv engine at 3k,5, 10,15 and finally 18k miles. You will see that the engine needs to be clsoe to 15k miles for the best power developed in a broke in engine. You can also do various compression testing of the cylinder to also read this information. A few Dyno testing shows those that do not follow a strict break in period DO NOT DEVELOPE close to what Mazda claims the engine power should be!

BTW the power is linear during the break in stage, and nothing is sudden or "freed" up at any given miles. This is with all new engines!

 

Interesting take Cali. Even with the S54 engine in my BMW M Roadster there is no mention of a 15k break in period. The important time (as per BMW) is the first 1,200 miles (they have a special service interval at that mileage when the oil is changed for the first time - which is even printed on a permanent sticker under the hood). After this you are free to run the engine as desired. Of course this is a mid 2000's engine design. Are you saying current motors require more of a break-in period than older engines?

 

Ah, the old trope about the “Italian tuneup” - but does it actually work, and what is the best way to do it? Not what’s been recommended above as it turns out. Before you try it on a modern direct injection vehicle, you may want to read/watch this.

https://www.roadandtrack.com/car-cul...-up-explained/

 

This is a MAZDA not a BMW and also a TM registered and under several Patent as well patent pending engineered and developed Mazda only Skyactiv engine.
I might add the BMW does not build all their engines as they once did. Many BMW built models use Chrysler engine LOL
And YES some of those have very long mileage in the 10-15k to be fully broke in!!!!
The except would be those that are built with plasma ceramic ring and a plateau finish hone with fully floating sleeves. LOL

There has been almost no documentation with any auto manufactures in decades about the break-in or wear in of engine and transmission. They realized decades ago that people are going to drive them as they way the way they know how. The warranties for engine damage caused by less than the best break in is rare. But then DYNO those engines from general public clearly shows less power fully developed and many do not even hit the specification mark claimed by the auto manufactures in their vehicle power information. I will say to that comment that most auto manufactures do not participate in the certification to post real engine power rating and can without posting that certification can use anything numbers they want in their power rating specifications. Mazda currently does not use the SAE J1349 or SAE J1995 to post real actual power ratings!

 

Interesting video!

they ask for a vote if it works. ROLMAO

That posted information should be named how to insure the high possible way to damage your engine!


In actuality about the only thing running your engine as described in that method would be on an engine decades ago Pre 90 and or older if a glaze was formed on your cylinder walls and the engine started to lose power because of not developing compression. Running the engine (after it had been health checked) at a high sustained RPM (still under RED line) will cause the compression rings to expand hard against the cylinder walls and usually remove the cylinder glaze restoring loss power.
Thats old school engines. It really has no place or value on newer engine with the type and material used in the manufacturing and assembling of engines.


On cell phone this morning so sorry for the repeated editing,,, darn tiny screen... hahahahaha!