Mustang gt 2021 smoke when downshifting and gas

[ledi5oh]

Why is this occurring? I’m catless but never had this issue and only realized when my friend drove behind me, is my pcv valve gonna need replacing, my oil dip stick was at minimum when checking so I will be filling with oil tomorrow

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[Justgonna send it]

Possibly unburdened fuel, are you tuned. And what weight oil are u running.

 

[ledi5oh]

5w30, I think the old owner put a ford performance tune but I didn’t tune

 

[Justgonna send it]

interesting. Have you attempted to get in touch with the previous owner to verify what they’ve done.

 

[ledi5oh]

Not sure how I can get in touch, I bought this at a ford dealership

 

[Justgonna send it]

Dang . Let put a pin in it and circle back later. So Out side of using oil and a little smoke. Is there any other drive ability issues? Check light’s etc?

Are you running catch can?
are you running high-quality fuel? (Shell or Exxon).

 

[Skye]

Used car. No cats. New York. Blowing smoke.

Was the car purchased in NY?
Were the cats already off the car at the time of purchase?
Will the car be registered in NY?

It's my understanding NY has inspections and emissions laws. If the OP has a solution, great. If not, depending on the circumstances, they might be able to return the car.

If the cats were already off at the time of purchase, they could have been removed for several reasons. Damage. A previous boosted application. Someone simply wanted headers.

I am seeing smoke in at least two separate instances, but also have a sense the car is smoking consistently, like there's a whiff of smoke almost always there.

- If the OP will be keeping the car, it's best to monitor everything well. Oil, fuel, coolant levels. Knowing the amount of oil lost at certain intervals, MPG per tank and if the car is losing coolant can help identify problem areas

- The car's PCV system could be an issue. PCV valves do fail. I can't remember more than one or two threads where it actually was the valve. It's often something else

- If there is a catch can on the car, it needs to be inspected and checked at regular intervals. Recently, another OP, another new purchase, had a breather/catch can setup which was overflowing it hadn't been emptied in so long

- Checking the inside surface of the tailpipes might help identify what is being burnt

- A detailed list of all modifications could help us provide more guidance

- A thorough inspection, front-to-back, top-to-underside, could offer several clues to the history of the car

- Digging deeper, removing the spark plugs and performing a compression test could give quantifiable information as to the health of the engine

 

[2015 Silver GT]

How do you plan to pass emissions without cats?

 

[sk47]

Hello; I am curious about the miles on the engine.

 

[ORRadtech]

Back in the day that was an indication of valve stem seals leaking or piston ring wear. IDK if it's the same in modern engines.
I'm also curious how a Ford dealer in the PRNY sold a car without cats and how the OP plans on passing emissions inspection?

 

[BullittTheBlueSky]

Purchased in NY, which has emissions testing, and de-catted.

I'll go with smoked #8 cylinder.

 

[warnerwh]

In Oregon it is illegal for a dealer to sell a car without cats. I bet in N.Y. it is the same.

 

[ledi5oh]

Dang . Let put a pin in it and circle back later. So Out side of using oil and a little smoke. Is there any other drive ability issues? Check light’s etc?

Are you running catch can?
are you running high-quality fuel? (Shell or Exxon).

I’m running no catch can but I have ordered one and I run 93 shell every time

 

[ledi5oh]

Hello; I am curious about the miles on the engine.

63k miles bought at like 60-61k, still have warranty until 100k

Used car. No cats. New York. Blowing smoke.

Was the car purchased in NY?
Were the cats already off the car at the time of purchase?
Will the car be registered in NY?

It's my understanding NY has inspections and emissions laws. If the OP has a solution, great. If not, depending on the circumstances, they might be able to return the car.

If the cats were already off at the time of purchase, they could have been removed for several reasons. Damage. A previous boosted application. Someone simply wanted headers.

I am seeing smoke in at least two separate instances, but also have a sense the car is smoking consistently, like there's a whiff of smoke almost always there.

- If the OP will be keeping the car, it's best to monitor everything well. Oil, fuel, coolant levels. Knowing the amount of oil lost at certain intervals, MPG per tank and if the car is losing coolant can help identify problem areas

- The car's PCV system could be an issue. PCV valves do fail. I can't remember more than one or two threads where it actually was the valve. It's often something else

- If there is a catch can on the car, it needs to be inspected and checked at regular intervals. Recently, another OP, another new purchase, had a breather/catch can setup which was overflowing it hadn't been emptied in so long

- Checking the inside surface of the tailpipes might help identify what is being burnt

- A detailed list of all modifications could help us provide more guidance

- A thorough inspection, front-to-back, top-to-underside, could offer several clues to the history of the car

- Digging deeper, removing the spark plugs and performing a compression test could give quantifiable information as to the health of the engine

I have had the car since may, I could bring it to a ford dealer because I have warranty until 100k miles

 

[Skye]

I could bring it to a ford dealer because I have warranty until 100k miles

I can think of two ways this situation could go:

1.) Purchased car from Ford dealer without cats. Here's another example.

https://www.mustang6g.com/forums/th...he-modifications-done-to-this-exhaust.225081/

In most states, it's illegal to sell a car like that. If the purchaser was out-of-state, one with no emissions, that could change things.

If the cats were off at the time of purchase, I'd sit down with that dealer and discuss a return. You might want to lawyer up. Nothing dramatic. I'd do a one-on-one sit-down first to get a feel for the dealer, warranties, returns and all that. Maybe a lawyer would later get involved. Maybe not. You also have the state Attorney General on your side.

2. ) Purchased car from a dealer and later removed cats. If this is the case, your warranty no longer applies. You've modified the drivetrain. All the dealer has to do is point to the lack of cats and mention the change in back pressure did the damage. They'll wash their hands of it. Read any Ford Warranty information.

Hopefully, this issue stems from a path 1 scenario.

Please keep us updated. I'd genuinely like to know if that dealer is selling cars like that, and who that dealer is.

Good Luck.

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