Skip the auto shop - Our mechanics make house calls

Q: p0171, back fires at idle, lack of power and red hot catalytic conterter?

asked by on

Got a code p0171 At idle it back fires. The engine has a lost of power, almost stalling. The catalytic converter gets red hot.

My car has 196000 miles.
My car has an automatic transmission.

A: The P0171 trouble code relates to a "l...

The P0171 trouble code relates to a "lean condition" and applies generally to many makes and models of cars. This simply means the air/fuel mixture is lean meaning that there is too much oxygen present in relation to the amount of fuel present in the system. This can cause a variety of problems, one of which you are describing which is a catalytic converter failure, turning red hot and stalling or loss of power. The catalytic converter converts otherwise toxic exhaust fumes into less harmful materials to expel into the environment. When this is clogged or not able to pass these fumes out into the atmosphere, it creates an enormous amount of heat in the car’s exhaust system as it backs up (think of a sink being clogged). I would recommend having an expert from YourMechanic come to your home to diagnose and repair the loss of power.

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: Water in car oil

There are several possibilities, but the most likely would be a head gasket failure. In any case, the cooling system will need to be inspected to find where the leak is. Do not drive the vehicle like this; the presence...

Q: Engine loses revs idling til the thing stalls

The most likely cause for your engine performance problem is a balance chain and fuel pump issue. GMC has released Special Coverage Adjustment 12313B which outlines replacement of the fuel pump and balance chain. A fault with either of these...

Q: Would a timing chain problem cause misfiring codes?

Hi there - yes, a worn or stretched timing chain, weak timing chain tensioner, or worn timing chain guides can cause misfiring, cam timing problem codes, low power and generally poor running of the engine. Most, if not all, of...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
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.