0302 Code - need advice
08-08-2005, 07:38 PM
#1
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0302 Code - need advice
From the sticky:
0302
Diagnostic Trouble code 0302 points to a problem with the Exhaust Gas Recirculation system. The malfunction is detected by the Engine Control Module when no EGR flow is detected under conditions which call for EGR. Possible causes include:
- 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
I got this code on my 97 Maxima. I don't have a dead battery nor a leaky exhaust system. I really don't know much about the EGR system and would like anyone's advice on what's most likely wrong. I am planning to sell my Maxima in the next couple weeks but want to take care of this check engine light before trying to do so. (I bought a Nissan pickup for practical reasons and have to get rid of the Max <sigh>)
Where do I start? Where is the EGR valve exactly?
Also, another question which may or may not be related. When inspecting my control arms/ball joints, I found a loose wire dangling near the oil pan. I found that it was torn from some sort of sensor that is installed into the oil pan itself. What can anyone tell me about that? I stripped the ends and reconnected the wire. The car seems not to perform any differently, though I have been watching the oil light when starting the car and it does flicker before going out. I don't know if this is a symptom of something or just my imagination.
0302
Diagnostic Trouble code 0302 points to a problem with the Exhaust Gas Recirculation system. The malfunction is detected by the Engine Control Module when no EGR flow is detected under conditions which call for EGR. Possible causes include:
- 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
I got this code on my 97 Maxima. I don't have a dead battery nor a leaky exhaust system. I really don't know much about the EGR system and would like anyone's advice on what's most likely wrong. I am planning to sell my Maxima in the next couple weeks but want to take care of this check engine light before trying to do so. (I bought a Nissan pickup for practical reasons and have to get rid of the Max <sigh>)
Where do I start? Where is the EGR valve exactly?
Also, another question which may or may not be related. When inspecting my control arms/ball joints, I found a loose wire dangling near the oil pan. I found that it was torn from some sort of sensor that is installed into the oil pan itself. What can anyone tell me about that? I stripped the ends and reconnected the wire. The car seems not to perform any differently, though I have been watching the oil light when starting the car and it does flicker before going out. I don't know if this is a symptom of something or just my imagination.
08-08-2005, 07:45 PM
#2
The wire is *most likely* from your oil pressure sending unit. It costs 15 bucks and takes 5 minutes to replace... posting a pic of the wire/sensor might help - since there is at least one other sensor in that area that comes to mind (Crankshaft position sensor).
EGR problems are hard to diagnose and fix. A common problem is the EGR port on the rear of the plenum gets clogged and the EGR guide tube that carries exhaust fumes back into the plenum gets clogged. You have to pull the plenum off the car to clean the tube and the plenum port.
EGR problems are hard to diagnose and fix. A common problem is the EGR port on the rear of the plenum gets clogged and the EGR guide tube that carries exhaust fumes back into the plenum gets clogged. You have to pull the plenum off the car to clean the tube and the plenum port.
08-09-2005, 04:47 AM
#3
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Thanks for your reply njmodi. I had already reconnected the wire from the oil pressure sensor, if that is what it is. I did take some photos of the area, but cannot find them. I think my wife deleted them before I could download them to the computer. Anyway, the car was outside last night and I couldn't get it in the garage to have a look under it. I'm not so concerned about the formerly loose wire because the oil light isn't on, and I'm having no real problems with the car. The check engine light is my biggest concern.
When you say the "EGR port at the rear of the plenum", where is that located exactly? Or even better, where might I find a schematic or even a photo of this system? Like I said, I really just want to get this car repaired enough to sell; I do not want to spend hundreds of dollars.
If I did reset the check engine light, what are the chances it would reappear immediately? It has been on steady for the last few months, but prior to that it would periodically go off by itself.
When you say the "EGR port at the rear of the plenum", where is that located exactly? Or even better, where might I find a schematic or even a photo of this system? Like I said, I really just want to get this car repaired enough to sell; I do not want to spend hundreds of dollars.
If I did reset the check engine light, what are the chances it would reappear immediately? It has been on steady for the last few months, but prior to that it would periodically go off by itself.
08-09-2005, 05:13 AM
#4
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Join Date: Jul 2003
Posts: 686
I had this code last yr for almost a month, I replaced EGR valve, code returned, cleaned out Throttle Body, code returned again, finally, I gave in, took it to a dealership, they replaced EGR solenoid valve and finally no Cel.
Check out these threads relating to your particular problem:
http://forums.maxima.org/showthread.php?t=393527
http://forums.maxima.org/showthread.php?t=350528
Check out these threads relating to your particular problem:
http://forums.maxima.org/showthread.php?t=393527
http://forums.maxima.org/showthread.php?t=350528
08-09-2005, 10:05 AM
#6
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Join Date: Jul 2005
Posts: 113
I have some posts in this thread Http://forums.maxima.org/showthread.php?t=418982
As per the link in my post in that thead, I removed the IAC , and went in through that
Opening to clean the egr port in the plenum, as I found this to be the easiest approach.
Removing as few parts as possible helps reduce the chance of damaging anything else.
No guarantee this is your specific problem, but as it’s a free fix , it’s a good place to start.
I have put additional 42,000 miles on the car since I did this repair and no cel since.
As per the link in my post in that thead, I removed the IAC , and went in through that
Opening to clean the egr port in the plenum, as I found this to be the easiest approach.
Removing as few parts as possible helps reduce the chance of damaging anything else.
No guarantee this is your specific problem, but as it’s a free fix , it’s a good place to start.
I have put additional 42,000 miles on the car since I did this repair and no cel since.
08-09-2005, 07:06 PM
#7
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Posts: 23
Well, I looked at the other thread and started to take everything apart this evening. I had a terrible time getting a wrench on the upper back bolt on the "plate" or the valve as you described it. It is definitely much more than a plate.
Basically I couldn't get that one bolt out, even rounded it over a tiny bit, so I gave up for tonight. I had removed all the air filter paraphenalia back to the throttle body just for better access. That was fairly easy. Yes, my throttle body is dirty but I didn't have an appropriate cleaner handy so I guess I'll clean that later, hoping that it'll make the car run even a little better before I sell it.
I studied the vacuum hose routing diagram for a long time, but still really don't know where the EGR valve is. It is very crowded in the engine compartment. I'm certainly not going to remove the whole intake manifold.
What did you use to remove the bolts holding the "plate" valve assembly? I got a 12 mm socket on two of them, but like I said, other components of that valve assembly got in the way and I couldn't get a wrench on upper rear bolt. I had a 12 mm open end wrench, and even removed a cannister-type apparatus (secured to the firewall) through which is routed the throttle cable, but still didn't have enough room to actually turn the bolt.
Basically I couldn't get that one bolt out, even rounded it over a tiny bit, so I gave up for tonight. I had removed all the air filter paraphenalia back to the throttle body just for better access. That was fairly easy. Yes, my throttle body is dirty but I didn't have an appropriate cleaner handy so I guess I'll clean that later, hoping that it'll make the car run even a little better before I sell it.
I studied the vacuum hose routing diagram for a long time, but still really don't know where the EGR valve is. It is very crowded in the engine compartment. I'm certainly not going to remove the whole intake manifold.
What did you use to remove the bolts holding the "plate" valve assembly? I got a 12 mm socket on two of them, but like I said, other components of that valve assembly got in the way and I couldn't get a wrench on upper rear bolt. I had a 12 mm open end wrench, and even removed a cannister-type apparatus (secured to the firewall) through which is routed the throttle cable, but still didn't have enough room to actually turn the bolt.
08-09-2005, 07:52 PM
#8
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Posts: 23
I found the thread in the How-to section on the IAC valve. It's the first item!! So I apologize for my last post. I'll have to give this a try again tomorrow night. I'll try to take some photos also.
njmodi: You're probably right that the best thing to do is remove the manifold and clean everything well. If I was actually keeping this car, I would consider that.
On the topic of having to get rid of my Maxima, is there a "support and therapy" forum for those of us who don't or won't have a Maxima anymore? I'm not sure if I'll be able to stand driving this Nissan pickup I bought; it's only a 4 cylinder! But it is 4WD, so I guess it might go places the Max wouldn't. My wife wants a minivan since we'll have our second child by the end of the year, so I'm definitely out of the performance market for a while. Her car is a Civic and I had the Max, now we'll have a put-put pickup and a sleepy minivan. <yawn>
njmodi: You're probably right that the best thing to do is remove the manifold and clean everything well. If I was actually keeping this car, I would consider that.
On the topic of having to get rid of my Maxima, is there a "support and therapy" forum for those of us who don't or won't have a Maxima anymore? I'm not sure if I'll be able to stand driving this Nissan pickup I bought; it's only a 4 cylinder! But it is 4WD, so I guess it might go places the Max wouldn't. My wife wants a minivan since we'll have our second child by the end of the year, so I'm definitely out of the performance market for a while. Her car is a Civic and I had the Max, now we'll have a put-put pickup and a sleepy minivan. <yawn>
08-09-2005, 08:04 PM
#9
lindenbusch - you can pull the IACV off and just use a coat hanger to try clean out as much of the crud from the EGR port as you can reach... pulling the throttle body off will help too - thats just 4 bolts as well.
Good luck.
Good luck.
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