2001 Qx4 P0171 error fixed... then not...HEELLLP?!?!? Silicone Air Filter??

[Gurthy]

Hi everyone.... I just bought a 2001 QX4 yesterday. This is my first post, and i hope you all can help. heres the situation.

I drove the car away from the owner after purchase, and the service engine light came on. i took it back to the guy and told him i wouldn't buy the car unless he took it in to the dealership to figure out the problem. Guy said it wasn't a big problem (he had a scanner and the code came up PO171 error bank 1). The guy said the reason it comes up with this error is because of the after market silicone air filter he put in. So he took the filter out.... then put it back in again.... and revved the engine hard for about 20 seconds. The service engine light disappeared, and the scan said the engine passed. He told me to replace the airfilter and all shoud be well. On my way back to my house (1 hour ride) the service engine light went back on. So i picked up a basic "Napa Gold" (non silicone) air filter and replaced the silicone filter. i then went through the process the seller did when the service light was on, but this time i didn't have a scanner. The light didn't turn back off. Its been a day now and the light is still on. The car runs great, and i don't notice any problems while driving. I don't have a scanner to recheck the error

I've heard the car needs to go through a full cycle in order for the engine to read the fixed error (unless you have a scanner) and the light should turn off. So my questions are...

How long should i wait until i give up on the fact that the error was an air filter problem? Has anyone else heard of silicone air filters causing this problem? I read the post about P0171 error codes, Does this seem like an airflow sensor problem even though the car still runs great.

Any help would be greatly appreciated. Thanks much

-Gurthy

[timmack]

since you dont have a scanner to reset the light...try unplugging the battery and leaving it unplugged overnight.

[Gurthy]

Okay so i bought a scanner, cleaned the MAF, and changed the filter, then reset the system.

Service engine light came back on a day later. When checking with a scanner code came up P0171 as it did b4. Does this mean the MAF is faulty, or could it be something else???

i've heard i should check for vacuum leaks b4 i get a new MAF. What is the easiest way to check for these leaks. how do you do it. Thanks for any help

[catsnet]

HeyI've been having this code along with two others for a last 2 weeks (yes i also have silicone filter) and yesterday was the first time the ECU curred itself without me scanning and erasing the codes. The reason is I stopped filling up @ Shell and popped some higher great fuel in it. Might be a coincident, but it works so far.Alex

[Gurthy]

okay... heres whats going on.. i purchased a brand new MAF and i was about to install it... when i realized...it might just be worth it to take it in to the Infiniti dealership... and get it diagnosed for 145$. So i know exactly what needs to be replaced and why. Stay tuned for the solution to this tedious P0171 code

[Gurthy]

Okay... at last.. the diagnosis was a faulty Mass Air Flow Sensor. It was replaced, and the P0171 hasn't come up sense... but new codes came up. P0420 and p0160. If anyone has had sucess fixing these.. let me know

[pathfinder_top_gear5]

Well glad to hear you fixed your original problem. I was going to say it seems like a faulty MAF sensor but you already fixed the problem

[Buzzman]

Sounds like the guy you bought it from already knew about the problems, and just cleared the codes before you bought it. A little bit unethical, but buyer beware.Having said that, I suspect you have one or more bad O2 sensors. This is a common problem on these vehicles. Nothing to get worried about, but it means more money of course. If you go to the dealer to have them replaced, which I suggest you do, then make sure they flash, or reprogram, the ECU. It should be free of charge. There is lots more info on this forum regarding the O2 sensor issues by the way, so you might want to do a search. Good luck. By the way, how many miles on the truck?

[timmack]

dont be so sure about the flash being free. every single dealer in the kansas city metro wanted to charge between $90-100 to do that. I also read, when i had this issue myself, that other ppl got stuck paying amounts in that ballpark too. it would be nice if they would do it for free, im sure some dealerships do. but call first and make sure.

[Buzzman]

Don't be so sure about the flash being free. Every single dealer in the Kansas city metro wanted to charge between $90-100 to do that. I also read, when I had this issue myself, that other ppl got stuck paying amounts in that ballpark too. It would be nice if they would do it for free. I'm sure some dealerships do. But call first and make sure.

Maybe it was just my local dealership being nice, or maybe it's a Canadian thing, but they did mine for free. Nissan knows about the problem, and shouldn't charge you for it.

[Gurthy]

My car has 74,000 miles on it. i will post a pic soon as i get one.

Dealer said the ECU probably just needs a reset. I've heard of people with the P0420 code needing to just update their ECU software or get it reset properly.

I put in the MAF filter my self and reset the ECU with a 70$ scanner. Guy said that might be the problem. Sometimes they don't reset right. Hope he's right *fingers crossed*

Don't have more money to keep pouring into a newly bought car. wish me luck. I'll update with the results