Skip the auto shop - Our mechanics make house calls

Q: Code p0421

asked by on

I am getting a p0421 code but I just replaced the catalytic converter. I got the code erased after but it popped back on. My car seems to stumble/put a lot though. What else could it be?

My car has 148000 miles.
My car has an automatic transmission.

Exception in rendering!

Message: Invalid string length

RangeError: Invalid string length
    at t.s.value (/tmp/execjs20170218-129495-15ofiayjs:167:15384)
    at /tmp/execjs20170218-129495-15ofiayjs:167:16113
    at f (/tmp/execjs20170218-129495-15ofiayjs:61:12326)
    at Function.Uo [as map] (/tmp/execjs20170218-129495-15ofiayjs:62:8878)
    at t.s.value (/tmp/execjs20170218-129495-15ofiayjs:167:15665)
    at m._renderValidatedComponentWithoutOwnerOrContext (/tmp/execjs20170218-129495-15ofiayjs:47:19688)
    at m._renderValidatedComponent (/tmp/execjs20170218-129495-15ofiayjs:47:19776)
    at m.mountComponent (/tmp/execjs20170218-129495-15ofiayjs:47:16076)
    at Object.o.mountComponent (/tmp/execjs20170218-129495-15ofiayjs:47:5085)
    at m.mountComponent (/tmp/execjs20170218-129495-15ofiayjs:47:16172)

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: Car battery can't keep a charge.

This may be a sign of a weak battery, a failing voltage regulator or failing alternator. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while...

Q: Crank no start on 2004 Ford Escape

Thanks for writing in about your 2004 Ford Escape. When the vehicle does not start, you need to check the fuel pressure and engine for spark. You should scan the computer to see if any codes are set that will...

Q: My car gauge goes to regular temperature, there's coolant in the system, but the heater doesn't blow out hot air?

Hey there. I would check the fuse for the heater control valves first. These are solenoid-operated valves which allow or shut off hot water to the heater core. If they are not opening, there is no hot water in the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
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.