Hackman

I've seen many posts that recommend the use of the OEM air filter element. Why? IOW, are "other" filter replacements that different?

I ask because I replaced my air filter element a year ago with one I picked up at the local auto parts store. My '91 LS didn't seem to run as well afterward. I thought it was just me. FWIW, the old filter was encrusted with all sorts of crud, the worst I'd ever seen. So, I was surprised that it didnt' run better and get better gas mileage (I get 15 MPG around town).

Do I need to switch back to the OEM replacement? Do I get it at Lexus or can I get an equivalent at Toyota and save money?

Hackman

C'mon, guys! Surely, someone has some kind of answer for me on this? I know I'm new but give me a break, will ya.<s>

One additional question: If I should be doing something like getting a new filter from Toyota (to save money), instead of Lexus, what part # should I be asking for?

Lvangundy

I didn't see your post!

Well...there's been so much discussion about air filters it's dizzying!

Your best bet for performance and good air filtration is to go with the stock toyota air filter. Sorry I don't have the P/N. There are quite a few Japanese market filters for the LS , but some are hard to get and no dyno testing has really been done by anyone here.

If you're looking for aftermarket, K&N makes two kinds of filters. One to replace the stock circular filter, and another cone type 'performance' filter. There's been a debate about the K&N adding any power on the LS cars.

Stick with the stock filter and try jbrady's mod he made by opening up the front of the black plastic filter housing to gain about 5HP.

Hackman

Thanks for the reply, Lvangundy. Yes, I've been searching on air filter and there are truly a ton of messages. However, most of them have dealt with modifying the air intake and I don't want to do that... at least not yet.<g>

After having some work done at a shop (which included an air induction cleaning), I've got a weird idle problem and I'm trying everything I can to eliminate the problem before I take it into the dealership.<f>

I found some of the discussions about the K&N replacement filter elements. Are these better than the OEM filter? I saw one post where someone had a MAF problem after using the K&N.
Since it's re-usable, I don't mind paying the extra.

Thoughts?

Lvangundy

A (maybe more) member in the GS forums found a K&N filter saved him alot of money over a year by not having to replace the cotton toyota filter every couple months.

My argument is that you can clean the toyota cotton filter by using a air compressor with a blower tip to clean out the dirt. It may not be the SAME as a new filter, but it still works. Toyota even specifies they can be cleaned with high pressure air. Eventually though you will have to break down and get a new filter.

Yes. Idle problems have been known to relate the the air filter and the MAF on the LS. Another thing to look at would be the throttle body (TB). These build up with carbon over the years and do need cleaning. You said you were not ready to open up the stock air filter so I'm assuming that you might not be up to removing the TB to clean it out. Be prepared to pay if you go to a shop to have them remove the TB and clean it. I recently removed my TB and cleaned it out - you can see pictures here.

https://www.clublexus.com/forums/sho...threadid=71021

If you want to go K&N try the stock-type replacement filter as nobody else here has really done it and it would offer a 'close-to' replacement for the stock filter. The K&N can be cleaned as needed with a 'recharge kit' that consists of a cleaner and a oil/ greasing element. Be sure not to over oil the filter as oil can get onto the MAF sensor and cause extremely low performance issues.

Also, be warned that some tests done by a BMW owner proved that K&N filters do let a small percentage more of contaminents and dirt through the filter. As mentioned the stock toyota cotton filter works the best and can be cleaned as the K&N can but only once or twice with high pressure air blast.

Hackman

Excellent info! Thanks, Lvangundy.

I'm actually not against modifying the stock air flow arrangement. I just want to put it off until I have this problem straightened out JIC I have to take the thing to the dealer. Don't want to "confuse" them with unauthorized alterations.<wink>

I am planning on cleaning the TB at the same time I replace the filter. As I mentioned, the shop did an air induction cleaning but I discovered today that it was done thru the air intake at front. I doubt this did much for the TB.

So, based on what I've read here on the threads, I'm off to get an OEM filter, some STP TB cleaner, and some Chevron Techron.

I'm unsure about one thing. Can you tell me if I need to be careful with the TB cleaner and the O2 sensors? I'm not even sure where the sensors are located.<f>

Hackman

Oops, just saw that you posted the link to the pics. Didn't realize that you were the one that did the TB cleaning example.

Any specials tips here? I don't have a shop manual and I've never removed the TB from my Lexus.

For example, when I reattach the TB do I need to torque the nuts to any special setting?

Lvangundy

This is taken directly from a PM I sent another member about the TB removal.

""HMM..where to start. I wish I would have taken more pictures when I removed mine.

Start with the air filter and it's housing. You have to remove the black hose and the black plastic hard elbow which curves directly onto the metal throttle body. This involves removing a few bolts in pretty obvious places.

Next remove the plastic cover directly over the throttle cables. There are 3 bolts here. Take have a screw driver and remove 2 phillips screws holding a small piece that looks similar to a motor mount.

There are 4 bolts holding the actual throttle body to the intake manifold. Three of them are easy to get to, the other is under the throttle body and you'll need an extension on your wrench to get to it. After all 4 are removed take a rubber mallet or somethign and loosen the body. The hard part here is that there are 2 hoses from the left and right sides of the thottle body (if you standing on the left side of the car) these are pretty difficult to remove, but just use some elbow grease.

There is a gasket between the throttle body and the intake manifold, but it's up to you to replace.

I might be missign a few small things here and there, but if you're up to the task of removing your TB anyway, I'm sure you can figure it out.

Just make sure you get ALL the carbon buildup out, otherwise the small (if any) improvement in driving will be alot less noticeable. After the cleaning the engine seemed to rev a little smoother on the highway.
""

TomWahjudi

Well, I have K&N replacement element (E-2606), so yes, there is at least one using it On '95 LS400 if you are curious.

TFW

Hackman

Well, I started working on this the other day and got down to the TB when I realized that I wouldn't be able to get it all the way torn down and back together that day. So, I stopped the disassembly at that point.

I did however get a good look inside. The outside of the TB looked really clean, but when I opened the butterfly and looked inside, I could see quite a bit of black gunk. Not as bad as Lvangundy's pics though.

Anyway, I went ahead and tried to clean it from the outside by holding the butterfly open, spraying in the TB cleaner, and then using my longest screwdriver wrapped in a shop towel to clean it. I got most of it out but there was some stuff on the sides that I couldn't quite reach.

I actually did try and start to remove the TB. However, the first nut I tried seemed extremely tight (didn't break loose with moderate pressure). It was at that point that I decided to wait. I thought I should probably confirm that I didn't need to do anything special when re-attaching.

Questions:
1. Is it pretty important/recommended to replace the gasket?
2. Does it need to be torqued to a specific setting or just tightened "good-n-tight"?