How many miles should the three-way cats on an Alfa Quadrifoglio last?

[vitamin]

How many miles should the three-way cats on an Alfa Quadrifoglio last? I'm at 29k and the startup and idle has gotten progressively rougher. I did a remote start today and saw a puff of sooty exhaust on the initial startup, and a gasoline smell. I know this car has a "feature" where, to warm up the cats at startup, it burns a very rich mixture for a few seconds, but I wonder if this could also be fouling the cats faster than we'd like if that extra gasoline isn't burning like it should.

I wonder how can you check whether the cats are clogged using OBD-II on one of these cars? I can see their temperature ranging from 870–1050° in some OBD-II logs, which seems like a normal range.

I read somewhere that the post-cat O2 sensor voltage should be flat, but I'm not sure if that only applies when idling or also when driving. (It's flat when idling, but pretty consistent with the pre-cat O2 sensor when driving).

Thanks for any input, I do plan to take it to the dealership for a look but like to get as much information as possible first.

Note: the car does use three-way cats, and as far as I'm aware the oil has always been OEM-spec ACEA C3 oil.

 

[Dave9]

They should last the life of the vehicle or until they rust out, whichever comes first.

Practically every vehicle runs a rich mixture at startup, before PCMs were in control, it was called a choke. Cats still lasted the life of the vehicle or until some other problem caused UNBURNT fuel, or excessive oil/carbon deposits.

Did it get progressively rougher or might you just have a bad tank of gas?

We should just wait to see what the shop states.

 

[Trav]

How many miles should the three-way cats on an Alfa Quadrifoglio last? I'm at 29k and the startup and idle has gotten progressively rougher. I did a remote start today and saw a puff of sooty exhaust on the initial startup, and a gasoline smell. I know this car has a "feature" where, to warm up the cats at startup, it burns a very rich mixture for a few seconds, but I wonder if this could also be fouling the cats faster than we'd like if that extra gasoline isn't burning like it should.

I wonder how can you check whether the cats are clogged using OBD-II on one of these cars? I can see their temperature ranging from 870–1050° in some OBD-II logs, which seems like a normal range.

I read somewhere that the post-cat O2 sensor voltage should be flat, but I'm not sure if that only applies when idling or also when driving. (It's flat when idling, but pretty consistent with the pre-cat O2 sensor when driving).

Thanks for any input, I do plan to take it to the dealership for a look but like to get as much information as possible first.

Note: the car does use three-way cats, and as far as I'm aware the oil has always been OEM-spec ACEA C3 oil.

Staying away from aftermarket oil additives is a good start. It must run richer at cold start the extra fuel has the same effect as a choke.

 

[bdcardinal]

Wouldn't this be covered under some sort of a warranty?

 

[CKN]

Wouldn't this be covered under some sort of a warranty?

Yea-should be Federal and/or state warranties that should cover those. Then there is the 3year/36 as well-I would think.

 

[2strokeNorthstar]

Alfa? 30k miles is normal. J/k. It should definitely be under warranty. CA is up to 7years 70,000 miles.

 

[OneLonelyBurrito]

The poof of smoke and gasoline smell at start up isn't atypical. The O2 sensor readings also sound normal. Nothing you described would lead me to a catalytic converter failure, there is almost always a code when a converter fails. In a former life, I was a catalytic converter engineer. We tested the cats at a little under 1000°C and its pretty typical for them to get to that temperature or above during a sustained loads. The cats should be the least of your worry with the Quadrifoglio.

 

[skyactiv]

Mass airflow sensor need cleaning?

 

[vavavroom]

Too bad they are 3-way and not 9-life cats.

Some cats will crumble over time and blow out the exhaust, others will crumble and cause a clog. I've had the first scenario happen to me but I have never worn out a cat due to contamination/combustion deposits.

 

[twouvakind]

From an Internet page:

Most components that fall under the federal emissions warranty are covered for 2 years or 24,000 miles, whichever comes first. The catalytic converter, emissions control unit (ECU), and the onboard emissions diagnostic device (OBD) are covered for 8 years or 80,000 miles whichever comes first.

I'm seeing states have varying durations of coverage.

Then you have manufacturer.......

 

[YZJB]

Probably carbon build up on the backs of the intake valves causing the rough cold start

 

[repairman54]

Italian car needs Italian tune-ups on a regular basis to keep those cats in magnifico condition.

 

[vitamin]

Did it get progressively rougher or might you just have a bad tank of gas?

Progressively rougher. First time I got a code, a few weeks back, it was a cylinder 3 misfire. The next time, last week on a cold morning, it was a multiple cylinders misfire.

Some forum threads indicate it's a problem with some of the '18/'19 engines, but the cause is mysterious. People say after restarting again, it's fine, and indeed I drove it with zero issues for a couple of weeks. Some say it's a clog in the PCV valve.

Was ready to chalk it up to condensation in the gas tank and put some Techron in, but today I got cylinder 3 misfire again on startup and it shut itself off after a few seconds. On the next startup I got "Service Engine" message so it's going in for warranty service.

I doubt it's bad gas. Feels more sputtery, like clogged injectors or something. Could also be carbon buildup as it's a GDI system.

From '20 onwards they went with GDI+PDI on these but I'm not sure those have the same issues.

We'll see what Alfa says. Overall it's been an amazing vehicle, first issue I've had with it.

 

[Dave9]

Misfires do (usually) send unburnt fuel through the cat(s), so I wouldn't be driving it at this point if you can work out alternate transportation, maybe a loaner vehicle from the shop?

 

[vitamin]

Misfires do (usually) send unburnt fuel through the cat(s), so I wouldn't be driving it at this point if you can work out alternate transportation, maybe a loaner vehicle from the shop?

Agreed, taking it to the dealer for a closer look next week.

 

[vitamin]

Also I found this to be interesting. Apparently back in 2020, FCA/MOPAR was worried about winter gasoline being sold to people in warmer weather causing "potential issues" in their cars, due to EPA relaxing regulations about not selling winter fuel in the summer and vice-versa. I read EPA's website linked in the bulletin below, and it only indicates the regs were being relaxed for one month.

However, on June 8, 2023, the EPA issued another new "Vapor Pressure Fuel Waiver" due to "extreme and unusual fuel supply circumstances caused by the ongoing war in Ukraine that are affecting all regions of the Nation."

On the hunch that perhaps my problem was just due to getting winter gas from a gas station who has never done me wrong before, I went to a different station and topped off 50% of the tank. So far, no more misfires at startup... crossing fingers!