Morning folks, I was having starter issues.. (Found drive was bad.) Before this, I was rack'n my brain trying to figure out the CEL reading the PO171 code. The rig runs great so I knew it wasn't something bad like I was hearing and or reading up on... RE; intake leak, bad injector/s etc. Well ya'll it's fixed!
During my starter R&R I found the air intake system was NOT put together correctly, it was all there but it wasn't connected at the driver fender! I got it figured out and back together correctly, after about 45miles of REALLY BAD running due to the battery disconnect for hours, I went to my parts house and had the CEL cleared and pray'n too the Maxima God's, no more CEL or PO171 code!!!

 

P0171 is bank 1 cylinders are running lean. An air leak after the MAF could cause this, but you indicated the leak was before the MAF. So unless there was another air leak that you didn't notice, you may get the code back. There is a good chance that you have an O2 sensor failing.

 

Yes.. It came back on, I will recheck for vacuum leaks FURTHER. Thank you for the reply and the suggestion about the 02 sensor. Have you ever used carb cleaner too locate intake leaks on these motors? I have on carbureted motors and found it useful. To tell you the truth. this is the newest rig I've ever owned my Wife's truck is a 2000 XE crew cab Frontier, I've been really lucky because I have always wanted both of these rigs. I was lucky enough too get both from the original owners, The Maxima was a/is an SE special order. RE: 17" with front and rear sway bars. Love this rig! Can the 02 be cleaned or, just replace it? Like I wrote (newest before these is 87)...

 

I have never had to use anything to help me find a vacuum leak. Mine were always obvious. There as lots of chemicals you can use for vacuum leaks. Carb cleaner works, starting fluid (ether) works, propane works - anything that is flammable. Even gasoline in a mister bottle! The more volitle (and more dangerous) the stuff is, the better the results.

As for the O2 sensor, it is unlikely cleaning it will help. O2 sensors are like a catalytic converter, when the active material is depleted, you have to replace the sensor. You can try cleaning the O2 sensor if you want, but I don't think it will make any long term difference. But if it keeps the light off for a longer period of time, it will have shown you that you are on the right track.

 

Your input is greatly appreciated. I trusted it enough too order all new 02 senders and send my Wife,Daughter and Granddaughter off too the coast in it. Thanks again and I’ll fill y’all in after I’ve done the work.

 

Hey all, I finally solved the issue with my CEL codes, I'm not gloating I am just posting it so maybe it can help another Maxima
owner so, maybe they won't have too spend the hours of hit and miss work I did. Anyway, what solved my problem is I removed the MAF censer and used about a half of a larger spray can of Berrymans MAF cleaner, cleaning it. I had to take it into the house after letting it drip all the cleaner off of it because it was cold out and it started too frost up. I didn't wipe it or use my compressor too blow it off, just let it dry real good, reinstall it. Good Luck!!
DaDeuce

 

Thanks for responding, most threads become dead ends after people get what they want. Couple of questions if thats ok. Wondering why was the MAF was dirty enough to throw a code.. Do you have a stock air box and filter? Do you consume a lot of oil?

 

Your welcome!
On your question of the reason for the dirty MAF, I purchased the car around Mid July and a day or so after the CEL pops up... I can only assume that they had cleared the CEL and left it sit until they sold it. Anyway, too make a long story short, no oil use at all and I still have the OEM air filter system on it. But believe me I have a lot of time in this rig, I have always wanted one. It hauls! Premium is kinda expensive but it’s worth every penny!!!
thanks!