nolyaw

I installe a K&N filter in my 93 ls, just to have a reusable washable filter, and My CEL came on throwing out a code 25, lean fuel mix. Now, its not possible for the new filter to flow THAT much more air, and the computer not be able to compensate, right? Could just be a coincedence. Anyone heard of this issue with a K&N in a first gen LS? By the way, I did pull the mass air meter and make sure it was clean and free of any oil. Any input would be great.

LiCelsior

iTrader: (32)

try disconnecting the battery for an hour and see if it still pops up.

nolyaw

I've reset it twice. It pops up when I'm the highway for awhile. I'm going to put in a standard paper filter and see what happens.

PureDrifter

iTrader: (10)

check fuel filter.

nolyaw

Already changed it. I was going to change all 4 O2 sensors, but then I thought of the K&N I put in. There is now way a ****ty little filter can flow THAT much more air, right? I will see if it stays off when I put back in a paper filter tommorrow.

jcrome04

Same thing happened when I put on a RMM intake on my old 91 LS. Code 25. Have your injectors pulled, soaked, and cleaned. Cleared everything up 100% for me! My injectors were just too dirty to keep up I guess.

nolyaw

Changed back to stock paper filter, same problem, code 25. Looks like I will be on to the O2 sensors.

Och

iTrader: (3)

K&N filter should never be used on cars with MAF/AFM sensor. The oil from the filter got all over the MAF, and its sending wrong reading to the ECU - less air volume than actually coming in, and in turn the ECU is sending too little gas. Your O2 sensors are good - they are correctly picking up the lean condition, thus the CEL. You can try cleaning the MAF and put in an OEM filter, but most likely you will need a new MAF.

PureDrifter

iTrader: (10)

i used to think this as well but it turns out the reason this legend exists is because people have a bad habit of over-oiling and under drying their filters.

a PROPERLY MAINTAINED K&N filter should work fine without issues, but if it actually gives a HP/TQ increase has yet to be determined.

nolyaw

I removed all excess oil from the filter before install. I've only had them in Ohhh...maybe 25 different cars or so. I dont know where people got that bs from...works fine in all Ford efi systems, BMW, MB, Nissan..etc. I did pull the maf out and check the cleanliness...spotless and dry. People go ape**** with oil after a cleaning of the filter, they are usually pretty good out of the box, I am confident the sensors are bad. The problem arrived with 2 changes: a new filter and a ****load of injector cleaner...I'll know by Wed.

Och

iTrader: (3)

Nope. About two years ago I put a K&N filter into my GS - I never oiled it or anything. A few month later the car started knocking hard under acceleration. Long story short, after $500 wasted at a diagnostics shop, I removed the MAF and the wire had a lot of build-up on it. Cleaned it and problem was solved. I'll never touch a K&N filter with a 10 foot pole again.

93LSexy

Run K&N filter and intake in every single cars I had. From trucks to twin turbos. Never had a problem with running lean or messing up the MAF sensor. But I alwasy make sure to soak up any access oil on the filter with paper towel prior to install the filter. I also reset the ECU and break in the filter little by little.
I personally feel a difference in my K&N, which have about 1K miles on it now. Especially on the high end, it really pulls much more now all the way to 6K RPM.
K&N has been proven to give 20% to 50% more air than varies OEM filters, so your ECU will acommendate with extra fuel. So if your injectors are clogged and fuel pump is weak, then you might run into the Lean Mixture problem.

trukn1

Dude,, first, calm down. There are alot of people here trying to give you advice on your problem. You may have clogged injectors, or a damaged MAF throwing the code so I would heed some of the advice given. There really is not a need for all of the foul language, you really are starting to come off as being arrogant.

93LSexy

If you are that confident...then why the post???

beggers can't be choosers...

jcrome04

Have you tried any of the advice given? Or just going your own road? I wouldn't mind hearing about what the problem actually is/was.