Skip the auto shop - Our mechanics make house calls

Q: Failed emission test, code P0071

asked by on

Emission test did not pass so I replaced the ambient air temperature sensor and went back. Still did not pass. What am I missing here?

My car has 88582 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. The code P0071 i...

Hi, thanks for writing in. The code P0071 is set when the AAT sensor IAT sensor and the ECT sensor do not correlate to each other after the vehicle has not been started for at least 480 minutes. One of the three sensors is not sensing the correct temperature. You need to scan the computer after the engine has sat overnight without starting it and look at the data of the three temperature sensors and see which one is not the same as the others. Then test and replace that sensor and clear the codes. If you would like help with this, consider having one of our expert automotive technicians come to your home or office to look at and diagnose these issues for you, and make any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
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

Get a quote

What others are asking

Q: Steering wheel hard to turn

With the steering wheel being hard to turn, this vehicle should not be driven until the issue is fixed as it presents a safety hazard. The most common cause of the steering wheel being hard to turn is the loss...

Q: Car with push button start won't start.

Hi, If by struggling you mean it cranks slow, low battery voltage might be the cause. Normal voltage on a fully charged car battery is 12.6 volts. On a vehicle like yours with a push button start, once the...

Q: P0405 EGR Sensor A Circuit Low

Hello and thank you for your question. With having 200,000 miles on the engine, I recommend replacing the EGR and not just cleaning it. The plunger is probably has too much carbon build up making the EGR stick open when...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.