the egr valve is underneath the air filter housing. WARNING: there are multiple things to cause the EGR system to malfunction other than the valve (BPT valve, broken vaccum hose, solenoid, clogged ports, EGR temp sensor). A good diagnosis would be worth being wrong by just replacing the valve. Trust me, I used to work for a Nissan dealer
Chat with our AI personalities
Code P1491 Means: EGR Valve Lift Insufficient Detected EGR Valve needs to be replaced
A P0402 indicates that the PCM is seeing voltages higher than expected from the DPFE(Delta Pressure Feedback Exaust) sensor. The DPFE is the EGR position sensor. The high than expected reading could be caused by an EGR valve that is either sticking open, EGR valve that is being held open by the EGR vacuum regulator, or it could be a faulty DPFE sensor.
Make sure you check the EGR valve, mine went bad and it gave me a multiple cylinder misfire code... It means it is misfiring on more than one cylinder. A new set of plugs and or plug wires may fix the problem. But it can also be many other things. Vacuum leak, fuel injector problem, etc ALSO coil packs can give you a code for multiple random misfires
im not shure i understand what you mean. if you mean can you change out for instance. a 2.4 engine out of a 97-2001 z24 with say a 97-2001 grand am the answer is yes. i have a 98 z24 and the engine out of it came from a 01 grand am. be shure to replace the new intake with your exsisting one and check for egr flow on the new motor