K&N 63 series causes lean condition and CEL

Don't Buy a K&N 63 Series system. Installed mine. Kept throwing codes. Tech stream at dealer showed lean condition both banks. Even at idle.
Said it was most likely K&N air intake. I removed and installed factory setup and no codes.
K&N said I needed to reinstall their stuff and then call tech to troubleshoot. Really?

Would not accept a return and said try to return it to 4 wheel parts to get money back.
I don't think they drove the test vehicle enough for it to throw a code for them.
This new 3.5 has narrow operating parameters.

Save your money don't buy a K&N for your 3.5 Tacoma.

 

Thanks for the post. I know neither intake or catback adds hp. But I was seriously itching to buy a K&N and flowmaster dual catback this black friday on autoanything.com

You've saved me $600.

 

most of the vehicles today need a tuner to program the new set up these days. no such thing as bolt on anymore. Not sure if the Tacoma needs one or not. Sounds like it does.

 

It did make more power and MPG was better than stock. I believe the lean condition comes into play when running at high loads and RPM.
IMHO the fuel system cant keep up. One day someone may come up with a tune that works better. Don't know if the port and direct injectors can be made to squirt at the same time giving much more fuel if needed.
I have a 2010 Taurus SHO w/ factory performance package and I installed a Hennessey kit with a tune. The darn thing screams and pulls like a train. If Toyota put a twin turbo on our 3.5L it too would be much better. Want a race truck? Put an ecoboost in your Tacoma. Ha

 

have had the aFe intake in for months, not a single issue.

 

That is good to hear. The AFE seems to be the better system. I think the 63 series K&N air velocity and turbulence where the MAF is located may be the problem. Just don't think they did a lot of R&D for the new motor setup.

 

I'll never buy any K&N product, and here's why. This is the throttle body on a Yamaha Grizzly that was running a K&N for less than 10 hours.

 

love it man and the sound is perfect, just enough while cruising and it will
roar when you stomp it.

 

I liked the sound also. Maybe K&N will come up with a fix.

 

I keep seeing all these negative posts about K&N and it has not been my experience at all in the past. I had their intake on both my old FJ and a S2000 prior to that. Put about 20k miles on the s2000 intake and about 15k on the FJ one. Never had a CEL on either and when I removed them before selling the vehicles the throttles and intake arms were still clean on both.

Neither developed any real power, but both sounded great and the throttle response seemed much better.

 

I have also put K&N on everything I have ever owned and no problems but hey its a new engine and all that. Who knows what Toyota engineers have done or what K&N didn't do.

 

this thread is so silly i love it.

 

From what I've seen in the past, at least with the S2000 and the WRX I had, intakes usually lean out the A/F ratio. Not a lot of people dyno the FJ and the Tacoma so I assume its just not mentioned as much here. Typically though it doesn't go lean enough to throw a code, unless your boosted like the WRX.

 

K&N type/style filters have been known to "clog" MAF sensors or any oiled gauze type filters due to the coating it can form if and when it's over oiled. This can cause a lean condition due to the poor reading and will not calculate properly, thus freaking out the ECU and displaying the CEL/ codes.

This is through experience of my own and customer's vehicles as a former dealership tech. I used to get all the "tuner" cars where I worked. You can pull live readings off the dealer scan tools and see the difference if the hotwire sensors are out of spec and feeding erroneous values. Usually can spot a dirty MAF pretty quickly if customer's tell you they replaced the filter with the oiled drop-in ( which won't void warranty, but some places will charge you diagnostic time if they find the result was a oily MAF unit).

I'm not sure if these 3.5 engines use a MAF though, I haven't looked into any of the engine management components at all. Last Toyota I had used a vane type air metering system. LOL

Those filters are not always what they're cracked up to be. I'd say the drop in panel filter is better as it retains the secondary charcoal filter to help block out any more particles and gunk, but you lose the "cool" noise.

The factory filters on these are usually best and the factory panel unit is shared with the Tundra running 2 extra pistons. We have CAI setup anyways on these Tacos.

 

Intake systems can be quite sensitive to changes. The ECU depends on an accurate measurement of airflow through the intake to determine how much fuel to add. An aftermarket intake system can change the airflow across the sensor enough to distort the readings more than the ECU is programmed to compensate for.

For example, some systems depend on smooth, relatively laminar airflow across the airflow sensor. OEM intakes are designed with this in mind, and are long enough that the airflow is relatively smooth by the time it reaches the sensor. Swapping this out for a shorter or more open intake can cause airflow to be too irregular or turbulent when it reaches the sensor, essentially removing the ECU's ability to accurately meter out the fuel.

This varies across car models and aftermarket intake systems, so you can't extrapolate K&N intake performance from one vehicle to another. In fact, we should probably be appreciative of the fact that the Tacoma ECU is smart enough to notice something is wrong and alert the driver.

For what it's worth, the performance gains from intake systems are usually very exaggerated. The positive reviews can usually be attributed to placebo effect from the purchasers. It is possible to gain a few horsepower and a minor MPG bump if an intake throws off the MAF readings or calibration enough to lean the engine out slightly, but that comes at the cost of running the engine too lean, which has other problems.

A lot of the claimed cold air intake systems actually do a worse job of collecting cold air than the longer factory systems. Note how the factory intakes are usually longer and extend to locations where they might reasonably scoop up fresh air, while these aftermarket systems are open to the hot engine bay. Sure there's slightly less air restriction, but you're also scooping up hot engine bay air.

 

My 08 had a K&N on it when I bought it. It sounds great, no CEL, but my scan tool shows Lean Condition both banks. If I can find a stock air box, I'll sell the K&N.

 

My 2013 Harley Ultra Classic hates KN filters too, lean running without a canned map on my Thundermax tuner.

 

My 17' has a K&N Intake

$300 63-9039 K&N Cold Air Intake System: High-Flow Air Filter, Increase Performance & Towing: Compatible with 2016-2023 TOYOTA Tacoma, 63-9039

63-9039, no issues, no CEL. Haven't noticed much change in the MPG, does feel stronger in the midrange, and sounds awesome when you stomp on the throttle.

They make a dry filter you can buy that requires no oiling, I'll probably grab one at some point but I've had K&N filters in almost every car I've owned and I've never had a MAF issue, just don't over oil the darn thing..lol

 

Good to know