Q: How to fix or figure out exhaust system leak code P0402

asked by on

The engine EGR system may have exhaust leaks at the back pressure transducer

My car has 133500 miles.
My car has an automatic transmission.

Hi there. The code you have denotes excessive EGR flow detected, not exhaust leaks. Anything on the EGR system could be causing this - a stuck open EGR valve, a stuck open switching valve/transducer, debris caught in the EGR diaphragm. Performing tests on this system should be performed by a qualified technician to ensure a proper diagnosis of the system and prevent the return of a Check Engine Light or drivability concerns. YourMechanic has several available technicians that can assist you with a Check Engine Light diagnostic if you would like to have an expert pinpoint the problem and guide you through repairs on site.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. How to fix or figure out exhaust system leak code P0402

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: Why does my 2009 GMC Acadia make a clicking/grinding sound when changing gears.

Hi there. there are typically two reasons why this occurs. I have seen this happen simply because the vehicles computer needs to be updated. If the programming is off it can cause enough of a delay in shifting to where...

Q: ESP, BAS, ABS brakes, Check Engine Lights are all on. What could be the problem?

You will have to have the computer scanned to see what the code is stored in the memory. I'm thinking that this code may be for one or more wheel speed sensor problem codes. All the problems could be from...

Q: White smoke coming out of car

Hello. Depending on what the smoke looks like and also depending on what fluids you are losing would help me to determine the problem. If the smoke has a blue cast to it then it may be burning oil. If...

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...
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.