P0171, K&N air filter...?

[dsmud4u]

Hello guys, I'm new to the 80 side of things. I have a 60 with 220ish on the clock. I know, pics or it didn't happen...I'll get to it soon.

I picked up a 97 40th anniversary edition. It has 266,000 miles but mechanical it looks sound, engine bay looks tidy and what we would call, a class one leak in the army, which is probably a rear main seal. I bought it for my wife to drive while I'm deployed this next year and might seek Yotamasters assistance for regularly scheduled service and to keep things up.

I put on a new Sears Die Hard platinum battery. I've ordered a Blackvue dr750s 2ch but it was defective so a new one is on the way. I ordered a new Mean Green starter since this one was going out and as preventive caution I ordered their alternator as well. I got the ARB 50qt hardwired and I'm gonna throw on some JW Speaker fogs as well. I'm gonna install a dual usb receptacle in the center console so the Verizon jet pack will constantly have power and so the phone will have a dedicated charger instead of hogging up the receptacle on the dash.

On to the problems. I recently Installed a new K&N air filter and on the way to work as I exited the freeway, the check engine light came on. I checked the codes and P0171 came up, Too lean I believe. I thought maybe it was a shear coincidence or maybe I exposed a crack in the intake tube. I cleared to the codes and drove back home and the truck still felt great.

My wife drove it this afternoon and the check engine light came back on with the same codes. I cleared them and installed the OEM filter, which might I add looks new. I started the truck and it idled very rough. I couldn't figure out why. I drove the truck around and thought maybe the CPU needed time to think and readjust to the air figures from the OEM filter and to my surprise, it worked. Back to normal.

I did some research and found no evidence of such problems on the 80s tech section. I was curious what all your thoughts were in your infinite wisdom, cruiser gods. Side note, I threw on the K&N again to see if the light came on again.

 

[ajax1]

Over oiled filter will dirty up the maf sensor pretty common on all vehicles, clean the sensor if it comes backs

 

[dsmud4u]

Over oiled filter will dirty up the maf sensor pretty common on all vehicles, clean the sensor if it comes backs

Yes, you are correct but the filter was brand new. It didn't appear overly oiled but I will clean properly and report back by tomorrow. The sensor that is.

 

[SteamerF18]

You already mentioned it, but check the air intake boot for cracks.

Also, the ECU needs some time to “learn” after the battery is disconnected and may run rough for a bit until it gets smart again. Don’t believe this will drive CEL and codes, hopefully someone more learned than I will chime in.

 

[BILT4ME]

Yep! The oil from the KN messes with the MAF as well as the readings from the O2 sensors. This has been documented on many different brands of vehicles, not just the LC/LX.

Just run the stock air filter.

KN makes money because everyone THINKS it gets better performance. A friend of mine had a 96 4Runner with a supercharger and watched a forum and graphs that one user posted that documented actual HP LOSSES from the KN vs stock filter setups.

I work in air and product filtration. To get more airflow, you open up the pores in the filter media, this decreases resistance. Opening the pores allows larger dirt particles through. Adding the oil helps to trap a bit more and under high demand the oil "pulls back" on the fiber out of the way, opening the pores for airflow. The oil will vaporize and contaminate the MAF and affect the burn in the cylinder (only to a small degree, but enough....)

Have you ever asked yourself why semi trucks and farm tractors don't normally use KN filters? Because they SUCK that's why! They do a VERY poor job of filtration. If all you EVER do is mall crawl, then use KN. If you're out in the dirt, use the factory one because that what it's designed to do!

Yes, disconnecting power for 2-5 minutes will allow the computer to reset codes and it will have to re-learn driving style. However, it can take as many as 30 run-off events to set a parameter. It is not run time or mileage based.

I will frequently unhook my battery prior to a long trip because it will clear my codes and setting of DD in the city. It definitely improves my mileage by one or two MPG when doing this.

Mr. T designed the system this way for a reason. Don;t just take my word for it..... Do a search on this forum for K&N and see that almost everyone that has installed a KN in the 80 has removed it and opted for the factory setup. The few exceptions will be those that go with Forced induction.

 

[Tools R Us]

... I ordered a new Mean Green starter since this one was going out and as preventive caution I ordered their alternator as well. ...

Have worked with some of their stuff, not impressed at all. Way over promised and under delivered.

... I recently Installed a new K&N air filter ...

They have much less surface area than the stock filter and don't filter as well. I would bin it for a Denso.

 

[dsmud4u]

Have worked with some of their stuff, not impressed at all. Way over promised and under delivered.



They have much less surface area than the stock filter and don't filter as well. I would bin it for a Denso.

Yes, I found out the hard way and even questioned whether or not it was the right part.

In regards to the Mean Green, I used their alternator on my 60. As we know, the stock one is ka-put the second you throw on a set of fogs. When I put the Mean Green alt. on my 60, it never did the high idle cycle and remained and a consistent RPM.

 

[dsmud4u]

Thanks BLT4ME. I didn’t think the 80 was that advanced in that it’s able to learn your driving modes. I will certainly disconnect the batt. Before long drives in hopes of improving fuel economy.

 

[ppc]

Mean Green is another product with a lot of hype, high price and is not as good as an OEM replacement. Its best to stick with OEM parts in the long run for reliability.

 

[madisonr34]

I had my k&n filter for over 30K miles on my 97 LX450.. never had a problem with it.

 

[Dave 2000]

Yep! The oil from the KN messes with the MAF as well as the readings from the O2 sensors. This has been documented on many different brands of vehicles, not just the LC/LX.

Just run the stock air filter.

KN makes money because everyone THINKS it gets better performance. A friend of mine had a 96 4Runner with a supercharger and watched a forum and graphs that one user posted that documented actual HP LOSSES from the KN vs stock filter setups.

I work in air and product filtration. To get more airflow, you open up the pores in the filter media, this decreases resistance. Opening the pores allows larger dirt particles through. Adding the oil helps to trap a bit more and under high demand the oil "pulls back" on the fiber out of the way, opening the pores for airflow. The oil will vaporize and contaminate the MAF and affect the burn in the cylinder (only to a small degree, but enough....)

Have you ever asked yourself why semi trucks and farm tractors don't normally use KN filters? Because they SUCK that's why! They do a VERY poor job of filtration. If all you EVER do is mall crawl, then use KN. If you're out in the dirt, use the factory one because that what it's designed to do!

Yes, disconnecting power for 2-5 minutes will allow the computer to reset codes and it will have to re-learn driving style. However, it can take as many as 30 run-off events to set a parameter. It is not run time or mileage based.

I will frequently unhook my battery prior to a long trip because it will clear my codes and setting of DD in the city. It definitely improves my mileage by one or two MPG when doing this.

Mr. T designed the system this way for a reason. Don;t just take my word for it..... Do a search on this forum for K&N and see that almost everyone that has installed a KN in the 80 has removed it and opted for the factory setup. The few exceptions will be those that go with Forced induction.

Have worked with some of their stuff, not impressed at all. Way over promised and under delivered.



They have much less surface area than the stock filter and don't filter as well. I would bin it for a Denso.

K & N were touted years back as a performance device donkey's years back, I tried them in three or four different vehicles over the years and found nothing to confirm that claim, in particular with vehicles fitted with carbs where fitting one would REDUCE power.

Unsure about the gassers as I rarely see them in the garage, but the OE air filter on the diesels is washable, I take a spare cleaned one when on a long trail and swap for the return home, reuse them a couple of times and then bin them.

Regards

Dave

 

[inkpot]

Mean Green is another product with a lot of hype, high price and is not as good as an OEM replacement. Its best to stick with OEM parts in the long run for reliability.

Putting tons of aftermarket crap on your 80 is NOT the best way to insure reliability for your wife while you are deployed.

 

[Tools R Us]

... I take a spare cleaned one when on a long trail and swap for the return home, reuse them a couple of times and then bin them.

Regards

Dave

Why, aren't the diesel filters cyclonic, have a tuna can, hard to believe that are that much less efficient that the gas unit? I wheel in the dust often, mess with the filter after ~3yrs, if that. Most of the dirt gets into the motor from filter service. Fresh filters are least efficient, they become better the longer they run, until they become clogged enough to cost power.

Put on one of these, Filter Minder® Graduated Position Air Filter Restriction Gauge - Threaded Mount Clean everything well, grease the seals, leave it alone till the gauge reads ~22-25, bet it will be years.

 

[ZackR]

My cruiser came with a K&N from the previous owner but I removed it once I saw how tiny it was (in diameter) compared to the OEM unit. I also spend a lot of time in the dust (that super fine flour consistency that gets in everything) and figured that it would be easier to dust out an OEM style filter thats dry than have to clean the dirty oil out of the K&N unit.

I do have a K&N in my M Roadster that I bought about 5 years ago and it still works fine (no codes, also not over oiled). At the time I thought the "performance" aspect was a real thing and haven't bothered to change it since it hasn't caused any issues.

 

[BILT4ME]

My cruiser came with a K&N from the previous owner but I removed it once I saw how tiny it was (in diameter) compared to the OEM unit. I also spend a lot of time in the dust (that super fine flour consistency that gets in everything) and figured that it would be easier to dust out an OEM style filter thats dry than have to clean the dirty oil out of the K&N unit.

I do have a K&N in my M Roadster that I bought about 5 years ago and it still works fine (no codes, also not over oiled). At the time I thought the "performance" aspect was a real thing and haven't bothered to change it since it hasn't caused any issues.

But I'm guessing your M Roadster ain't out in the dust.......

 

[ZackR]

But I'm guessing your M Roadster ain't out in the dust.......

Exactly... although this time of year I'm getting anxious to clean off six months of garage dust and get it out on the road.

Side note... about five years ago in the roadster I was headed up going to the sun road at glacier national park. It was under construction and there was a mile or two of gravel road so I took it easy, no biggie just some dust. On the way back they watered down the road turning it into a muddy mess. The combination of the mud from the road, mud splashed by oncoming traffic etc... the roadster was 100% covered in a thin film of red mud top to bottom. I had to use the wipers to see out the windshield and they were streaking mud the whole time.

Lets just say when I'm underneath I still find spots of mud on top of the control arms, exhaust heat shields, etc... It was a literal ih8mud moment.

 

[Dave 2000]

Why, aren't the diesel filters cyclonic, have a tuna can, hard to believe that are that much less efficient that the gas unit? I wheel in the dust often, mess with the filter after ~3yrs, if that. Most of the dirt gets into the motor from filter service. Fresh filters are least efficient, they become better the longer they run, until they become clogged enough to cost power.

Put on one of these, Filter Minder® Graduated Position Air Filter Restriction Gauge - Threaded Mount Clean everything well, grease the seals, leave it alone till the gauge reads ~22-25, bet it will be years.

Got a snorkel Tools, that helps heaps?

Yes there is the cyclonic and tuna can. Fresh filters are less efficient, not buyjng that one mate, remember there is no manifold restriction on a diesel, the more clean air the better, I will carry on swapping.

Re dust, a lot of the trails are covered in dust here that can only be described as black talcum powder, a vehicle moving slowly 30 or 40 yards in front if you can lift enough of this ultra fine powder or dust you cannot see anything, you have to stop and wait for it to settle before moving on, a 150 - 200 yards really is the minimum distance between each other assuming a speed of about 15 - 20 MPH.

IIRC in OZ the 80 gets a filter blocked warning on the dashboard, there is wiring for it on some 80's, not if they are petrol or diesel though?

Regards

Dave

 

[Tools R Us]

Got a snorkel Tools, that helps heaps?

I don't and our experience says they don't do much. Never seen seen a significant difference, we know what dust is.

Yes there is the cyclonic and tuna can. Fresh filters are less efficient, not buyjng that one mate, remember there is no manifold restriction on a diesel, the more clean air the better, I will carry on swapping. ...

Nothing to buy, but check this:

Sorry to hear about the diesel filter, Toyota did a great job on the gas intake. If the diesel has special needs, too bad they didn't give it an proper filter.

 

[Dave 2000]

Really interesting video and thanks for taking the effort to post. It has some very valid points but many not applicable to the 80 diesel or petrol models.

For example, the air intake on most heavy commercials (in particular those used in dusty conditions) are not low down or under the wheel arch, as per the 80, they are high up wherever practical, think snorkel here.

On the diesel 80 with the intake from filter lid to turbo, it is impossible to drop dust into the turbo and subsequently into the inlet manifold, lift the lid pull the filter, wipe the canister put a new or washed filter in, replace lid, and of course empty ye ol tuna can.

I note you often cite the settings or guidance from Toyota, as the way to go when answering a question posted on the forum by those new to the model, and I completely agree with you, Toyota advise washing the OE filter (on the diesel) out. I cannot remember how many times you can do this, but for me probably twice and then renew, perhaps this is because they only use the diesel 80 in hostile environments, think dusty here.

Re snorkels, I have I guess half a mile or more of unmade road just to get to my front door? With rain only having made an appearence twice this year it is very dusty. Not using my 80 as example as I also do not have a snorkel however, my TD5 owning neighbour does or rather did have one. Last year he wss forced to remove the snorkel and have the hole in the wing welded up by the inspection station, I mentioned this at the time on the forum in my own long running thread (link in sig). He normally has a yearly service replacing all filters, and at 6 months just a change of oil and both oil filters, now he has to have a new air filter as well! I really do believe snorkels do help keep the air filter clean, and having witnessed this first hand on his car, and having seen an 80 with the (IMO) ugly round clear plastic snorkel 'pre filter' with debris in, this more than justifies keeping the filter changed regularly.

As an after thought and perhaps relevant, given that inlet manifold vacuum increases as the filter medium starts to reduce air airflow, any weakness in a gasket, loose clip, or the all too common split in the air trunking, air (along with contaminants) would be drawn in avoiding the filter altogether.

I do see the sensor you fitted and think it is a great idea, there was one on a truck I used to drive, I also saw this was being used in the video, and as per my earlier post is fitted on the Australian 80, there was other good advice about blowing out or banging the filter, useful for those needing training in this area.

I will stick with my regular changes, anal or OTT matters not, for the couple of minutes it takes me I am happy to know it has been done.

Regards

Dave

 

[Tools R Us]

Really interesting video and thanks for taking the effort to post. It has some very valid points but many not applicable to the 80 diesel or petrol models.

That is a brief version of their bigger document that I can't find, called something like changing the air filter is killing your motor. Agree every platform differes, you may live on the dustiest road on earth, have the longest hose, etc, good for you! All of that is irrelevant. The point is changing the filter by emotion, more often than needed, is not doing the best for your motor.

The larger document more fully explained their research, basically showed that most of the dirt ingested over the life of a well maintained motor came from filter changes. Filters have a much longer usable life than most of us were taught, so changing them by data, only when needed is much better for the motor. Because setups and use conditions very, the only/best way to know when to service them is by using a restriction gauge.

... I note you often cite the settings or guidance from Toyota ...

I agree with most of their guidance, air filter is one of the things that I disagree with. For example, they recommend dunking a dirty filter in a bucket of water to clean. The dirt goes into the water and onto the inside/clean side of the filter, how could it not? It's impossible to remove all of it, so, when dry, installed, the pulsating intake vacuum flow dislodges it directly into the motor. That combined with the other pitfalls of cleaning them and seeing how long their useful life is, I wont be buying cleanable filters. Good Denso filters can be had for ~$10, for my use, only needed about every 3yrs or 40k mi, likely much longer for those who run in less dusty conditions.

For most of my life, I also serviced filters way too often, that is what was taught in the automotive field. Running the restriction gauge has been highly enlightening. Doing it this way there is significantly less debris in the throttle body, intake piping, etc. Last time I changed the filter the gauge was at 18in/h2o, the old filter was heavy, likely 3 or 4 times more than the replacement. Next time will weigh them, from what I observed, will be at 20-22in/h2o.