p0304 - cylinder 4 misfire
p0300 - random/multiple misfire
p0171 - system too lean (bank 1)
p1320 - ignition system/mnfctr. control


any troubleshooting or steps to resolve?

 

I would look at your ignition coils. I got the same codes when my coils were going bad. I would suspect that your coils haven't been changed. If you have new coils they will have a grey dot on the top of them. Do a seach on ignition coils and you will get plenty of toubleshooting advice (check stickies if you don't know how to search) Also check stickies for Dave B's number he can get you new coils at a great price.

 

You will most likely need to replace your coils...

 

Jokey - you beat me to it :-)

Check the 5th Gen For Sale threads. twilln is selling a set of used ones for a good price (I bought one set from him already :-)...

Edit: add the thread for coils for sale...

http://forums.maxima.org/showthread.php?t=413406

 

P0304 - Cylinder 4 Misfired Detected
P0300 - Multiple Cylinder Misfire Detected
P0171 - Fuel Injection System Too Lean (Bank 1)
P1320 - Ignition Signal

Your car gives the P1320 code whenever something is wrong with one or multiple ignition coils. The P0304 code is a clarification code and telling you that cylinder 4 is the ignition coil that needs to be replaced. Please do not buy all 6 coils and waste your money. Everybody on this board seems to think that you need to update all of them. I did my own investigation of the coils (found one that I thought was bad) and replaced that one and the engine code turned off and hasn't come on since. The P0300 code confuses me because it seems that it should just read out an error with each individual cylinder instead of saying just one, but then saying multiple, so in that case you may want to check into replacing more. (I disconnected each coil and looked at the spark plugs and saw which ones had a darker tip than the others and that's how I decided which one was bad)

As far as the P0171 it sounds like that may be a problem with an 02 sensor bc 02 sensors regulate the air/fuel ratio and a bad one could cause the car to run too lean which isn't good bc that means its not giving enough gas to the car and could potentially be harmful. (mine is running rich currently and i'm getting poor gas mileage and some black smoke under hard acceleration and i had the P0135 code). If others confirm my suspicion of an 02 sensor needed then you should go to www.oxygensensors.com They have great prices and customer service and free priority shipping.

Good luck. Let us know how it turns out.

 

i'm just replaced my spark plugs (NGK) and i'm putting the new MAF in today...

 

xplosive9z... from what I can recall, if it is only one cylinder mis-firing then it will call that cylinder; however, if there is more than one mis-fire then you will get the 0300 code. As for how many to purchase, that is totally up to you. I just replaced my MAF, coils, O2 sensors (both front), and plugs. I was having multiple codes thrown like yourself.

If any information I give is incorrect I am sure the more senior members will correct me but I am pretty confident that what I said is true. BTW.. cylinder 5 is a bish to get at.

 

P0300 - Multiple Cylinder Misfire Detected... If I were you I would replace them all considering that one or more already failed and that 2K coils are very weak by design you may as well get them all done esp considering that you are replacing all plugs...

 

What mod did you just do?

 

lol... yep.


looks to be coil number 4. swap it with another, go for a drive and pull the codes again, if the miss followed replace that coil. you shouldnt diagnose a lean code with a misfire present. take care of the misfire first, then if the lean code comes back, find out what it is.

 

#1 cause of P0300 codes is an air leak somewhere. #2 is a defective coil....thats why I ask

 

E55AMG2... Take a look at another post he has... swapping out CAI for stock box... could be the root cause?

 

It very well could be