How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29518
Experience:  GM Grand Master Technician 2007. 14 years experience.
Type Your Chevy Question Here...
GM Tech (Cam) is online now
A new question is answered every 9 seconds

Chevy impala: 2002 and it has code p040 im wondering if i can drive it

This answer was rated:

my car is an chevy impala 2002 and it has code p040 im wondering if i can drive it like that until i fix it?

Welcome to Just Answer and thank you for asking your question. I look forward to helping you fix your vehicle.


I will try my best to help you and in order to do that, I need you to describe the issue in as much detail because I only know as much about your vehicle as you have told me in your post, so my answer will be based on what you have posted. Please include all the small details that may seem insignificant such as warning light, codes that you have scanned and how this started. I will also try my hardest to help you avoid a dealer or shop, but with the modern vehicles an electronics, there may come a point that we cannot avoid this, and if that is the case, I will tell this.


My goal is your satisfaction and I ask that you not accept unless you are satisfied, but if you are satisfied, please accept so I can receive credit for my work and time. Positive Feedback is greatly appreciated and bonuses are always welcomed.


Please feel free to reply as needed.


I will need the rest of the code. There should be 4 numbers, not 3.

Customer: replied 7 years ago.

ok its Po420


OK, this is for the converter. Do you have any lack of power, odd smell or any other issue other than the code?
Customer: replied 7 years ago.

yes when im driving up hill it smells like hot rubber or something burning the code says catalyst efficiency below threshold (bank1) no thats the only issue

OK, the smell is enough to worry me. I don't recommend you drive it like this. This can result in engine damage because of the added heat from the restriction in the exhaust. Also I have heard nothing but problems using an aftermarket converters.
Customer: replied 7 years ago.

do i have to take it in for repair or can i fix on my own? an i can i drive it short distances? like to the store?


Short distances, yes. Change it yourself, yes, these are very easy to change with a couple tools and the ability to get under the car safely.
GM Tech (Cam) and other Chevy Specialists are ready to help you