Boost issue 2021 ecoboost

[keno199]

I am trying to determine what might be causing a low boost issue. I scanned with Forscan and no codes.

2021 XLT, 76K miles, no issues until recently.

The boost will only build to half of the boost gauge and the truck is sluggish on acceleration. I usually run 87 and tried 91 to see if it would help, it did not. I used Boostane and ran a mix of 94, it did not. Nothing helped with octane ratings, still half boost.

I cleared the adaptation across all modules, drove the truck moderately to recalculate the tables. Once calculated I floored it, and the boost returned to almost full boost gauge with the return of power.

Drove for a few more days and back to half boost and sluggish performance. Cleared the adaptations and the power returned. No codes are ever presented. I don't know if there is a failing wastegate, but no codes support a mechanical failure.

The truck in 100% stock. There are a couple of changes i made with Forscan but none impacting performance.

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[powerboatr]

Obvious question
Mpg change
Air filter condition
Oil consumption change

 

[JJSnell]

I am trying to determine what might be causing a low boost issue. I scanned with Forscan and no codes.

2021 XLT, 76K miles, no issues until recently.

The boost will only build to half of the boost gauge and the truck is sluggish on acceleration. I usually run 87 and tried 91 to see if it would help, it did not. I used Boostane and ran a mix of 94, it did not. Nothing helped with octane ratings, still half boost.

I cleared the adaptation across all modules, drove the truck moderately to recalculate the tables. Once calculated I floored it, and the boost returned to almost full boost gauge with the return of power.

Drove for a few more days and back to half boost and sluggish performance. Cleared the adaptations and the power returned. No codes are ever presented. I don't know if there is a failing wastegate, but no codes support a mechanical failure.

The truck in 100% stock. There are a couple of changes i made with Forscan but none impacting performance.

I agree with @powerboatr, when was the last time you replaced your air filter? Or confirmed it was? Autoshops are pretty notorious for 'replacing air filters' and they dont. If its a reusable, (Banks, K&N, etc), when was the last time it was thoroughly cleaned? You can boost all day long, but if airflow is blocked, its blocked....

 

[keno199]

Obvious question
Mpg change
Air filter condition
Oil consumption change

sorry should have included: new plugs, new air filter, no oil consumption, oil is clean. No odd sounds. MPG is 20 hwy, 15 city.

 

[SALEEN961]

Can you tell us what the learned OAR (octane adjust ratio) or KOM (knock octane modifier) is when you're experiencing the issue?

 

[keno199]

Can you tell us what the learned OAR (octane adjust ratio) or KOM (knock octane modifier) is when you're experiencing the issue?

Sure. I am guessing this is stored in the adaption table. Where is it located in Forscan?

 

[SALEEN961]

Sure. I am guessing this is stored in the adaption table. Where is it located in Forscan?

Unfortunately I don't think Forscan is able to display these pids and most scan tools can't either. These pids are extremely helpful when it comes to diagnosing issues like this but they are usually only readable with an SCT, HP Tuners, or similar tuning device.

 

[keno199]

Unfortunately I don't think Forscan is able to display these pids and most scan tools can't either. These pids are extremely helpful when it comes to diagnosing issues like this but they are usually only readable with an SCT, HP Tuners, or similar tuning device.

thanks. I don’t have those and there is not an error code.

 

[SALEEN961]

My guess is that your truck is learning a very high OAR / low KOM due to false knock. This would explain why clearing the adaptions returns your truck to normal boost levels while also explaining why higher octane fuel didn't help and why there are no codes present.

Check for anything in the engine bay or around the exhaust that might be loose, hitting, or making noise.

 

[powerboatr]

You also could do a data log run
But requires a driver
Your laptop
And select all the pids for baro pressure,
Cylinder contribution
All the good stuff under ecm
Boost, etc. No more than 20, as it's aton of info
Put it in graph so easier eyeballing
Sit in passenger seat and have someone drive

 

[Henfield]

Take the time to follow all the hoses from the air intake, onwards until they enter the air now boosted, heated and intercooled enters the engine. Look for damage (impact or rodents), loose clamps, loose hoses....

Best done with a cold engine........

 

[keno199]

Take the time to follow all the hoses from the air intake, onwards until they enter the air now boosted, heated and intercooled enters the engine. Look for damage (impact or rodents), loose clamps, loose hoses....

Best done with a cold engine........

I will. It seems like a loose hose would kick off a code. Why would power restore when the adaptations are cleared.

 

[SilverSpur]

I am trying to determine what might be causing a low boost issue. I scanned with Forscan and no codes.

2021 XLT, 76K miles, no issues until recently.

The boost will only build to half of the boost gauge and the truck is sluggish on acceleration. I usually run 87 and tried 91 to see if it would help, it did not. I used Boostane and ran a mix of 94, it did not. Nothing helped with octane ratings, still half boost.

I cleared the adaptation across all modules, drove the truck moderately to recalculate the tables. Once calculated I floored it, and the boost returned to almost full boost gauge with the return of power.

Drove for a few more days and back to half boost and sluggish performance. Cleared the adaptations and the power returned. No codes are ever presented. I don't know if there is a failing wastegate, but no codes support a mechanical failure.

The truck in 100% stock. There are a couple of changes i made with Forscan but none impacting performance.

I would return all settings back to stock and see if anything changes. Then add back changes 1 at a time to see if any issues.

 

[keno199]

I would return all settings back to stock and see if anything changes. Then add back changes 1 at a time to see if any issues.

The changes made were Bambi lights, and disable double honk when the key is removed and the trick is running. Changed 3 years ago when I bought the truck.

The boost loss is increasing. Last night I data logged, then cleared adaptations and data logged again. Full boost returned for about 15 miles and started dropping off again. Drove about an hour this morning and now making about 40% boost.

Did Ford push an update that might be janky?

Should I flash the truck back to as built?

 

[SilverSpur]

I am trying to determine what might be causing a low boost issue. I scanned with Forscan and no codes.

2021 XLT, 76K miles, no issues until recently.

The boost will only build to half of the boost gauge and the truck is sluggish on acceleration. I usually run 87 and tried 91 to see if it would help, it did not. I used Boostane and ran a mix of 94, it did not. Nothing helped with octane ratings, still half boost.

I cleared the adaptation across all modules, drove the truck moderately to recalculate the tables. Once calculated I floored it, and the boost returned to almost full boost gauge with the return of power.

Drove for a few more days and back to half boost and sluggish performance. Cleared the adaptations and the power returned. No codes are ever presented. I don't know if there is a failing wastegate, but no codes support a mechanical failure.

The truck in 100% stock. There are a couple of changes i made with Forscan but none impacting performance.

How is the fuel pressure? A clogged fuel filter can cause the low-end power loss.

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