Just bought the k&n 33-2052 from ajusa.com (thx to all for the tip)...it came in 4 days...i have a couple quick questions:
1) still not sure the diffs between the one K&N recommends for the rx versus the 2052...when i removed the factory oem filter it was smaller then the 2052...the 2052 fits, but its definitely a slightly diff fit...anyone know why the 2052 has been recommended on this board versus the k&N recommended one?...

2) no diff in mpg yet...i have not disconnected the battery lead yet and will do tonite...didn't know if it was a requirement -- and there's mixed recommendations on this topic...i also am driving 77-78 speed to work each day...not sure if this speed hurts me, but i thought i'd at least see something...

any help would be appreciated...

Rob

 

I got the recommended filter from AJ a few weeks back too.

It seemed to fit ok, I don't know how the fit differs from the one K&N recommends.

I disconnected the ECU fuse to reset the computer. I haven't noticed any change in MPG at all. I also switched to Mobil 1 at this time, and again, no change in MPG.

Don't expect too much. I guess the filter will pay for itself over the life of the vehicle.

 

i disconnected the positive battery terminal for 1/2 hour and then took a long trip today...no noticeable diif in mpg...will keep my eye on it, but others are claiming 8-10%...not seeing it...oh well...

 

just a stupid question....

did you replace your whole intake or just the air filter? Please let me know, I am really interested to find out if really get some mileage improvements

 

i replaced just the filter...it's only been a couple of days, so i'm still checking it out...i live in Upstate NY and the weather has been rather rainy and snowy -- which affects my normal driving...with this said, though, i think i'm seeing a 1MPG increase (from 18ish to 19ish)....nothing dramatic...my work commute is 45 miles each way and i'm travelling between 65-78 most of the time...not sure if the speed has an affect on how the car breathes...will update when i get more feedback...Rob

 

I have used a K&N filter in Mexico City (high altitude is perfect for it) for almost two years. Never reset the engine, as it gradually adjusted to the filter. Normally, you get about 13 mpg with this type of car (and the bad gas loaded with sulfur). The K&N filter increased it up to about 15-16 mpg.

One thing I did notice was an excessive amount of K&N oil getting on my MAF, and it did cause a check engine light. Rather than wipe all the oil off the filter. I just wiped it off the side that does not face the air inflow.

The K&N dealer not surprisingly sells the highest volume of K&N products anywhere in the world for a single dealer.

 

thx for the info...and my check engine light indicator did come on -- stayed on for 2 days, then went back off...i did reset the engine (by removing the positive battery terminal) and then drove the car ...the engine indicator didn't turn on right away -- probably after a couple hundred miles and 8+ hrs of hiway driving...i'll check on the oil issue...so -- do you think the mileage will improve over time once the computer senses the increased airflow?...i hope so...still not sure why people on this post recommend the 33-2052 over the k&n recommended 33-2145...i put the 33-2052 in -- and it fits -- although it's a little larger than the original stock lexus one...

 

I have the 33-2052 sitting in a box. My current filter is the newer model of the K&N. At this high altitude here in Mexico City, I have noticed a definite improvement. There is 25% less oxygen here than at sea level, so you can imagine the car wants all it can get.

I am almost positive you are getting an OBDII failure of fuel trim lean. Nothing to be concerned about, but the it does mean the air flow has changed enough that the computer could not compensate quickly enough. It should go away.