I just replaced all three O2 sensors this weekend and that problem is now out of the way. But I'm still pulling up the code 0302 for the EGR. I've reset the codes 3 time and still get the EGR one after about 60 miles or 4 engine starts. The possible causes in the stickies are:

- The electrical harness or connectors (valve circuit open or shorted)
- The EGR valve is stuck closed
- Weak or dead battery
- The EGR passage is clogged
- Faulty EGR temperature sensor circuit
- A leak somewhere in the exhaust system

My question is, which one typically is the cause? Just spoke to a dealership and they told be about 50% require a Valve change. Anyone have any ideas or opinions? Has anyone ever had to change this valve? It seems tough to get to...Thanks for your help in advance.

 

Getting to the valve is a pain.

If your light is "persistent", i.e. reappears right after your clear the ECU codes, then you might have a component failure (valve, solenoid, etc.). If the light comes on "eventually", it might be a blocked passage. The EGR guide tube and the EGR port on the upper intake manifold are prone to clogging. I would recommend cleaning those out first - its free (other than time and a few gaskets). The valve is not cheap - 100 bucks or so. I wouldn't replace it without knowing that it was indeed failing.

To clean the guide tube and the port on the plenum, you have to pull the plenum off the car... thats not fun.

 

No, the light doesn't come on immediately. The valve costs $140.44 at the dealer plus gaskets. I haven't had a chance to price it out at other places.

I don't have my haynes manual handy but does it describe how to clean out the EGR?

 

The cleaning isn't really documented as a procedure or maintenance item. Its just the way things seem to happen on our particular engines. Once you pull the upper IM off (you can use the Haynes to help you with that), you'll see the EGR port on the back (behind and under the IACV). You'll see that it is likely clogged with carbon. You will also notice the EGR tube (which connects to this port from the EGR valve) will have lots of deposits/blockages. I'm not guaranteeing that cleaning out the tube and port will fix your problems, but it is definitely worth the try. Here are other threads on the matter:

http://forums.maxima.org/showthread.php?t=90535
http://forums.maxima.org/showthread.php?t=403116

 

Wow, does that clear up a lot of questions. I think I will go for the EGR selenoid valve cleaning/possible replacement to start out with.

Do you think I can pass emissions with this problem? I need to pass by the end of the month and not sure if I will have time to do this before then. I am thinking of resetting the code just before I get there and let the engine cool down.

 

I think there's a way that they can tell you've reset your ecu, and haven't given it proper time to readjust/retest (200 miles IIRC), and might fail you for that reason. There was this one guy that posted a thread like that a while ago.

 

Hey i have got a quick question, could not log on to post new thread so i thought i would post it here.I am going to replace my front left bank o2 sensor(from the code)but i dont know whick on that is. It kinda depends on which side of the car you are standing on at the time.I know there is a front left and a front right bank.Please help me and tell me which on is the front left bank.Is it the one closest to the front of the car or the one inthe middle between the catalatic converter and the very front one??? Help please...Thanks in advance

 

Front left O2 is the one closest to the front of the car.

 

^^ that's correct... and for future references...left and right are determine while looking at the car sideways from driver side unless otherwise stated (sitting inside vehicle or oustide vehicle <-- case you are facing your engine bay fron the front of car)