Cold air intake issues (K&N) (P0171 code) "system too lean"

Hey I was wondering if anyone might've had similar issues as me. I recently installed this K&N cold air intake and it immediately threw on my check engine light after 1 day of driving. I've noticed some stalling and hesitation when I am accelerating. I need to clear this light because I have to pass the California smog check. The error code reads p0171 "system too lean". I've tried looking for vacuum leaks with no success, I even cleaned the mass air flow sensor but the code still comes back after I clear it. I'm getting to the point where I might just throw this K&N expensive junk in the garbage and go back to stock. The only issue is my stock intake has literal gigantic cracks in the plastic and is unusable, I would have to purchase another stock airbox. Any tips or advice would be great before I go and purchase a new stock air intake.

 

The new intake itself is not likely the issue. Cleaning the MAF doesn't mean the MAF is still good. You're going to need the FSM (search around the net, it's easy to find) and test it to see if it's still in spec.

 

Most likely if after CAI install is the oil from the filter gunking up the MAF or vacuum leak/unmetered air. I’d clean the MAF again just to be sure, and then start looking for any vacuum connections you may have missed, splits or cracks in the ones you did connect, cuts in or loose couplings, or cracks in the elbow. There are threads on here for techniques on looking for vacuum leaks if you want some other ideas/inspiration. Good luck!

 

Un metered air being drawn in past the maf sensor which can be a pain to find at times.

To much oil on the filter has your Maf dirty already

 

https://www.yourmechanic.com/articl...e-code-system-too-lean-bank-1-by-andrew-quinn

 

I used to work at Kragen Auto. Do not run K&N oiled filters on any Toyota, it will F up your MAF Sensor.

Leave it stock. Zero gains from anything aftermarket.

 

throw that hot air intake away and put bck the oem one

 

Disconnect the battery for about 10 mins, clean the MAF sensor with MAF cleaner and then reconnect and let it idle for about 10 mins. Let the system learn the new CAI. I had similar issues and that clear it up. If that doesn't work, I hear buying a new MAF will work too.

DO NOT OVER OIL THE FILTER. It just needs a light, even coating.

Worst case, sell the CAI and buy a new airbox on RockAuto and do the Deck Plate Mod.

 

Erroneous. Like most things, technique maters. Myself and numerous others run K&N CAIs with zero issues. And I mean zero. I really dislike misinformation.

 

Not a CAI, but I've run the same K&N reusable filter for 20 years now without "F'in up my MAF sensor"- so add me to the numerous others who run K&N with zero issues pile.

 

I used the drop in K&N style filter first before switching to the CAI. Neither one caused issues and I would buy them both over again. Using a product and using a product correctly can be two different things depending on who's performing the task at hand. A few poorly executed uses of a product is all it takes for the masses to paint in broad strokes about how something is awful when it really isn't.

 

Holy fuck- I just looked at the prices for a new K&N CAI.. I could build a handful of custom carbon fiber tubes for that cost!

 

I think I paid about $300 for mine new about six years ago.

 

Stock is a CAI. Drop-in is the way to go.

 

Heads up the Disinformation Governance Board was disbanded.

We had so many Tacoma owners come back with issues with drop in K&N’s. It was always Tacomas.

It was shocking, since then I won’t run oiled filters.

Maybe they were over oiled back then

 

there is nothing new about the idea that oiled air filters screw with the sensors in modern vehicles and its hardly misinformation. Just because you haven't had problems with yours doesn't mean its not a possibility.

 

Oh I agree.. It just blows my mind that they charge $330 (reusable cone filter is $70, retail is $399) bucks for a tube and clamps. Maybe I should start making carbon tubes and selling them...

 

Lol. homie.... I am not the only one who hasn't had problems. The "issue" is people do dumb stuff on repeat. This dumbness is so ubiquitous that it becomes mainstream. These dots connect themselves for me. Different frequencies is the nicest way I can put it. And I really am trying to be more forgiving, because if it weren't for all the fools in society I might not be in the fortuitous position that I am.

 

Oh for sure, it's stupid. I made both my entire intake systems, two cone filters and intercooler included, for less than that.

 

So someone drops in an air filter, car has problems and now they are dumb?

It’s on Google so it must be facts.