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TheRedRascal

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After I Returned my car to stock to switch my tuner, my car started throwing codes p0171 and p0174 and its also dying (loosing power at low rpms) nothing wrong with my intake and ive cleaned my maf sensor,not undrstanding why its dying when coming to a stop, getting frustrated can anybody point me in the right direction to find the problem so i can come up with the solution?
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SheepDog

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What parts did you remove?

Is there Ethanol in the tank?

You sure you don't have a vacuum leak?

Did you flash the OEM calibration after you returned to stock?
 

loucas-2021

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Sounds like the Air/Fuel mixture is too lean on Banks 1 and 2 from your codes. Most common cause is vacuum leaks. Your tuner should be able to help you out with that. Is your CEL on? +1 on flashing the OEM calibration.
 
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TheRedRascal

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What parts did you remove?

Is there Ethanol in the tank?

You sure you don't have a vacuum leak?

Did you flash the OEM calibration after you returned to stock?
i was running e85 when the vehicle was tuned i ran the tank back down to 3miles and filled it with 93 before i reurned it back to stock, as far as parts go i only changed the roush cai back to the stock cai.and no i didnt not flash the oem calibration how would i do that?
 

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i was running e85 when the vehicle was tuned i ran the tank back down to 3miles and filled it with 93 before i reurned it back to stock, as far as parts go i only changed the roush cai back to the stock cai.and no i didnt not flash the oem calibration how would i do that?
So you have a new tune flashed on the car for 93 Octane and the factory intake? Is the Roush CAI the same diamater at the MAF housing as the OEM intake? (No tune required type)

You probably have a leak somewhere between the MAF sensor and the intake manifold.

Check for loose hose clamps, make sure the breather tube from the intake to the drivers side valve cover is installed correctly, the MAF sensor is seated in its hole properly etc.
 
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TheRedRascal

TheRedRascal

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Sounds like the Air/Fuel mixture is too lean on Banks 1 and 2 from your codes. Most common cause is vacuum leaks. Your tuner should be able to help you out with that. Is your CEL on? +1 on flashing the OEM calibration.
im not familiar with my cel or it being on, i dont hear any unusual hissing or sucking noises coming from the vaccum lines
 

SheepDog

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no my stock tune on the car with 93
I edited my response above. Id bet you have a leak somewhere. Start the engine and let it idle. Get a can of brake cleaner or carb cleaner and spray short burts around the intake tube, MAF sensor, throttle body, breather tube to the drivers side valve cover. If there is a leak, the engine will suck it in and the engine speed will change. Also make sure you didn't damage any pins on the MAF connector
 
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TheRedRascal

TheRedRascal

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no my stock tune on the car with 93
im waiting for my new tune file to be sent over
So you have a new tune flashed on the car for 93 Octane and the factory intake? Is the Roush CAI the same diamater at the MAF housing as the OEM intake? (No tune required type)

You probably have a leak somewhere between the MAF sensor and the intake manifold.

Check for loose hose clamps, make sure the breather tube from the intake to the drivers side valve cover is installed correctly, the MAF sensor is seated in its hole properly etc.
i dont have my sound tube(breather tube the same thing?) installed on the stock cai i deleted that, that could be the cause ? and i guess thats what you meant when you asked did i uninstall any parts lol my bad
 

SheepDog

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im waiting for my new tune file to be sent over

i dont have my sound tube(breather tube the same thing?) installed on the stock cai i deleted that, that could be the cause ? and i guess thats what you meant when you asked did i uninstall any parts lol my bad
Do you have the plug in the intake for the sound tube delete? No, the valve cover breather tube goes from the intake pipe, to the drivers side valve cover fitting

1723760254186-i8.png
 

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Check all of these locations for correct installation. There are O-rings insde the fittings, make sure they are intact and not broken or pinched. Make sure the MAF sensor is sealed properly against the intake tube and of course the clamp and intake tube section at the throttle body

Intake leaks points.jpg
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