Q: I have a p0174 code that was reviewed on a scanner.

asked by on January 20, 2017

I have cleaned the MAF sensor twice, I have replaced all 4 02 sensors. I have checked for vacuum leaks by hazing the engine with brake cleaner. I am still getting a primary code p0174 and a second p0132 code on my OBD. Any advice would be greatly appreciated. Thank you

Hi there. The code P0132 in on for an issue with the upstream oxygen sensor. There could be a broken wire, frayed wire touching something metal, or the sensor could have failed. The code P0174 is on for the Mass Air Flow sensor (MAF). The MAF sensor could be dirty, has failed, or the intake plumbing could have leaks between the MAF sensor and the Barametric Pressure Sensor (BPS). Since you have cleaned the MAF sensor twice, then check the all of the clamps to the intake plumbing and make sure that there is no leaks. If there is no leaks and the clamps are tight, then I recommend replacing the MAF sensor.

If you have replace all of the oxygen sensors and the code is coming on for a failed or disconnected sensor, check the wiring to all 4 sensors and see if there is a frayed wire or a broken wire. All it takes is 1 broken wire to set the code.

If you need further assistance with your engine codes solutions, then seek out a professional, such as one from Your Mechanic, to help you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I turn off the Air Bag Light on the dash?
If the Air Bag Light on the dash of your car is on, it means that something’s causing the passenger sensing system to turn off the front air bag and possibly the side air bag. Here’s what you should do...
Car won't accelerate after 10 miles
Hello. It is more likely that the cause of this problem is that the catalytic converter is clogged which would cause the car to not to accelerate once becoming warm. There could also be a problem with the transmission. Your...
No power when accelerating
A faulty throttle position sensor can most certainly duplicate all of the symptoms that your Mercedes is experiencing, however a faulty fuel pump or even a defective mass airflow sensor can be the cause to these issues too. I have...
Can it take time for power steering leak damage to show up in the rack and pinion?
Hello. Yes, this is possible. A bad pump or leak can starve other vital components in the steering system causing them to weaken. When this occurs it can take days, weeks, or even months for them to finally fail. I...
The car will start fine may run for 20 miles then shut down stopping at a light, but will restart.
The code listed usually points to a malfunction in the throttle position sensor circuit. It makes sense the vehicle will shut down as the vehicle cannot operate safely if the control system cannot properly calculate the correct throttle position. As...
How do I get the monitors on my car ready for SMOG test?
Hi there. Take a scanner and check the computer (ECM) for any codes that could be pending. Check to see what the codes are and correct the code by performing the repair on the area that is not working or...
Transmission problem?
Hi There, It sounds like your vehicle may be a bit low on transmission fluid (https://www.yourmechanic.com/services/transmission-fluid-service) or you may potentially have a bad transmission control solenoid. As you know, the transmission works on hydraulic pressure built up from the fluid...
Brand new battery. car won't start 1996 Saturn SL. Went to the store just fine. Go to leave won't start, made noise, now nothing.
Hello, thank you for writing in. The first thing to check with your starting issues (https://www.yourmechanic.com/services/car-is-not-starting-inspection) are the connections to the battery. Make sure the battery cables are clean, dry, and tight. From there, you will want to look into...

Related articles

How Car Keypad Locks Work
Pioneered Pioneered by Ford, keypads let you lock, unlock without keys Pioneered by Ford, keypad door systems began appearing on high-end car and SUV products in the early 1980s. Ford took advantage of the then-new digital computer revolution – the...
Symptoms of a Bad or Failing Mass Airflow Sensor
Common signs of problems with a mass airflow sensor include running rich at idle or lean under load, decrease in fuel efficiency, and rough idles.
P2078 OBD-II Trouble Code: Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High
P2078 P2078 code definition Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High What the P2078 code means This code will set if the Engine Control Module (ECM) (https://www.yourmechanic.com/parts/engine-control-module), or Powertrain Control Module (PCM), detects a problem with the position...