# Running rich. P1101 P0173



## Cruz15 (Mar 17, 2016)

*Google says.

Wiring or vacuum?
Not a mechanic. Good luck though. Could the boost sensor be way off, faulty causing everything? Was the fuel trim way off to start? 

What causes the P0173 code? *


A dirty or faulty mass air flow sensor
Leaking intake manifold or torn intake boot
Vacuum leak
Faulty fuel injector
Faulty fuel pressure regulator
Pinched fuel line
 * What are the symptoms of the P0173 code? *


A Check Engine Light
Increased smog or soot from the exhaust
Loss in acceleration
Hesitation or misfire during idle
Increased fuel consumption
 * How does a mechanic diagnose the P0173 code? *


Visually inspects the mass air flow sensor
Tests the resistance of the mass air flow sensor and circuitry with a digital multimeter
Performs a fuel pressure test
Inspects the wiring of the fuel injectors for fraying
Inspects the intake manifold and vacuum lines for leaks
Uses a scan tool to specify the fuel trim out of range (short-term or long-term)
 * Common mistakes when diagnosing the P0173 code *


Replacing the Mass Air Flow Sensor without cleaning or testing it first
Deeming a component faulty without checking for more common causes, such as vacuum leaks
Not using a scan tool to determine if there is an issue with either the short- or long-term fuel trim
Failing to inspect the wiring of the component thought to be at fault
 * How serious is the P0173 code? *


The life of the catalytic convertor could become shorter because it will have to filter more pollutants in the exhaust gases
Gas consumption will increase
 * What repairs can fix the P0173 code? *


* Replacing the mass air flow sensor *
* Replacing the fuel pressure regulator *
* Replacing the intake manifold gaskets *
Repairing or replacing the engine air filter intake system
Replacing a vacuum line connected to the throttle body
Repairing a leaking brake booster
Replacing a damaged fuel line
* Replacing a faulty fuel injector *
 * Additional comments for consideration regarding the P0173 code *

It is suggested to always check the wiring of a component and clean it before deeming it faulty. It's also a good idea to check the intake system and vacuum lines for leaks.


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## Cruz15 (Mar 17, 2016)

A member fixed his P1101 by, Removing the throttle body and cleaning it 100% put it back together, didn’t even clear the code. The computer recognized the problem was fixed after 2 run cycles and went away. Could a stuck Throttle body cause that much boost?


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## Zach_The_Kidd (10 mo ago)

Cruz15 said:


> A member fixed his P1101 by, Removing the throttle body and cleaning it 100% put it back together, didn’t even clear the code. The computer recognized the problem was fixed after 2 run cycles and went away. Could a stuck Throttle body cause that much boost?


I wouldn't say it causes 14psi at idle, but it could cause a rich code by it being stuck. We decided to replace the air volume controller and she hasn't brought it back, so I'm assuming that fixed the issue. It was weird seeing the wastegate open at idle.


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## Zach_The_Kidd (10 mo ago)

Cruz15 said:


> *Google says.
> 
> Wiring or vacuum?
> Not a mechanic. Good luck though. Could the boost sensor be way off, faulty causing everything? Was the fuel trim way off to start?
> ...


If Google gave me anything useful I wouldn't have created an account here lol. I went through those tests by the book, found the fuel trims were actually running rich and that it was making way too much boost at idle(these cars apparently make 14-16psi peak according to another thread on here). Replaced the air volume controller and she hasn't brought the car back since. I wouldn't be surprised if she burns it down and claims insurance on it lol. Problem after problem with it.


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## 17Hatch6MT (Dec 28, 2015)

Maybe the 14 psi is an absolute pressure reading? At sea level, add 14.7 psi to 'gauge pressure' to get absolute pressure.


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