Obd code 405
 

Hello, This is my first post on this forum , My problem is i have a 2002 4.3 engine , The obd code reader pulls up code p405 which is egr valve , Now they say that this particular engine does not have a egr valve , I've burnt up the internet Trying to find the egr valve on this engine , Even went to the Chevrolet dealership trying to locate it , They couldn't find one for it either , So my question is why would 2 different code readers be pulling up code 405 for an egr valve that is not there , Could it be reading the purge cannister that's on rear of intake manifold instead or rear of the plenum , Any help would be Greatly appreciated Thanks

its right on top of the engine on the front of the manifold. just what dealership did you take it to!? EGR is normal Federal emissions requirement, so there is no way unless someone put a Marine intake manifold on that truck before you owned it that its just 'missing'
https://cimg9.ibsrv.net/gimg/blazerf...5d84b86e43.jpg

Vehicles are not required to have EGR valves, they are required to meet the applicable emission standards. Some engines use an EGR valve as part of the strategy to meet that requirement. The 2002 has no EGR but the 99 does. I have no idea why a non-EGR valve motor would generate an EGR code. My curiosity about your post sent me to the Google but I could not find any discussion of this situation either.


George

well thats new to me, also very very strange since i dont think 2002 had anything different from a 2001 or a 2003 truck mechanical or tuning wise, wonder if thats why my truck is acting odd at idle, being an 03 block with a 99 intake manifold.

reed: trying to understand what you actually have; you say you have a 2002 engine?...are you saying that you have a different year Blazer with a 2002 engine in it? If an engine swap was done, the ECM had to also be changed. What does your OBD II scanner show to be the year of your Blazer?

A 2002 Blazer 4.3L engine does not have an EGR valve.

That could explain it, a non OEM combination of vehicle, engine, ECM. Phantom EGR pain.


George

There is no P0405 on a 2002 Blazer. If he has an earlier year Blazer with a (non-egr) 2002 intake manifold, then the electrical connector is just hanging and is the cause for the P0405.

So what year is the vehicle? Has someone switched the ECM? What is the vehicle vin per scanner ID (does it match acutual vin)

IMHO it is not good to switch PCMs with a 4.3 Engine swap as the PCM controls and is calibrated for many more things than just the engine. Just switch the intake and exhaust manifolds from the original engine onto the new one. Other than the possibility of Knock sensor differences, they are equivalent.