Unsolvable P0171 'System Too Lean' Code

Yes not having to open up the hood every time..

 

Haha yes!!

 

The instructions on cleaning it are good, but you don't have to remove the whole airbox.

 

Yeah, I just took the sensor off itself, really easy. The video I watched showed the guy removing the air box too, but he was also cleaning the throttle body.

 

Lol yeah I see now in that video that he didn't clean the little air temp sensor (the bulb looking thing) and he didn't use MAF sensor cleaner. Smh

 

yikes, I don't get why some people think carb cleaner or electrical cleaner is okay....MAF cleaner is only like 8 bucks, just splurge for it!

 

Exactly. You're gonna use it all eventually anyways. Especially after doing in the first time and realizing it takes 5 minutes haha

 

Good news is...I washed my '04 today and she looks pretty.

Bad news...my CEL is back on guess the MAF wasn't the issue. CODE P0171 'system too lean bank 1'

Taking it to Toyota tomorrow to see what they say, wish her luck

 

I'm no mechanic, but these are my guesses. Bad MAF, fuel filter, o2 sensor or small vacuum leaf (I would check the PCV valve...Good Luck. All those are pretty much maintence stuff except for the MAF and 02 sensor.

 

.

.

 

Thanks, yeah I'm hoping it's just a dirty sensor issue or some other maintenance related issue. Cleaning the MAF didnt do the trick so possibly one of the other things you mentioned. Fortunatley I'm still just within the 30 day bumper to bumper warranty I was given from Toyota when I got it so it should be covered. Worst case scenario from what I've read related to this code is that my catalytic converter is bad, but hopefully that's not the case.

I'll keep y'all posted

 

I should mention that both times this code popped up was right after giving her full boost/open throttle. So in a way it's likely related to the supercharger I'm guessing.

And yes, I always fill up with premium and even add octane boost from time to time.

 

Also FWIW the truck runs and drives fine, no rough idle or anything like that.

 

So did you ever figure out if you jave the 7th injector installed on yhe truck?

That could very likely be the issue especially since you mentioned the code pops after a good hard romp on the motor in boost...

 

90% sure I don't, going to ask the tech tomorrow to verify for me. That could be the case but its just hard to imagine that TRD wouldn't make it a part of the s/c kit if it was that critical to keeping the motor from running lean. According to them, the blower was designed to work with the stock fuel system. But sounds like I should invest in it anyway

 

Elevation has alot to do with how the S/C performs. I agree TRD shoulda supplied everything needed to make that thing run flawlessly. Even though they say its supposed to run fine with stock fuel system, but again elevation determines alot. Heck even lots of peeps run a higher pressure fuel pump too when going charged to avoid issues. So, idk.... Was your charger dealer installed or did the PO do it? Even if the dealer did it they might have just slapped it on there and call it good and not bothered with the extras....

 

It was dealer installed, along with the TRD headers and exhaust all at the same time. I figured they put so much effort into TRD'ing it out lol that they'd be sure to equip it with the fuel system it needs, but being that Toyota did it they probably thought to trust TRD's recommendation that it would run just fine on the stock system.

FWIW I live in socal, a couple hundred feet above sea level. I do think I remember reading somewhere on here that a blower has a harder time with fuel the lower your elevation (or maybe I have that reversed). At any rate, I think a URD 7th Injector kit is in my near future.

Anyhow, oddly enough (of course) the check engine light was off this morning when I started up my truck. I still had an appointment with Toyota so I brought it in anyway, figure I might as well get this taken care of while I can if it's a sensor that needs cleaning/replacing, or something else. I'll keep you guys in the loop, thanks for the replies!

 

Ok so Toyota called me back, apparently it IS still my MAF sensor. They want $450 to replace it, christ. I asked him if they could try cleaning it and he said they don't do that they just replace them lol.

Question: is replacing a mass airflow sensor as easy as cleaning one? I'm looking them up online and they're less than a hundred bucks, so I have no idea why the dealership wants almost $500 for it. Is it just a plug in and go type of repair? Or is there more involved (computer, wiring, etc.) that makes it more of a process? I'd rather just do it myself and save a lot of $$ if I can

 

Simple. Remove the old like you are going to clean it. Instead of cleaning it, replace it with a new one.

 

It should be cover under the 30 days warranty bumper to bumper. Why they want you to pay???????