TRD Intake Second Gen, P0101 Code

I know the second gen TRD intake for my 2011 Tacoma has caused problems for people with it throwing codes and running lean.

Mine recently started throwing the P-0101 code. But here is the thing, it didn't start throwing codes until my first oil change from dealer. Drove it for over 4k miles code free with the intake on. We even drove it from Az to Cali 2 times with no issues at all.


I bought the truck with 94 miles on it and put the intake on at 125miles. Both my wife and I drove it for 4,000 miles and never once through a code. Take it in for my first oil change, my wife is driving it home from the dealer and it throws the P0101 code. I clear this code using a scan tool, about 200 miles of me driving it so far so good. Wife gets in, 5 miles later code comes on. I clear it with my Torque app on my phone and it didn't come back on.

We got home, I cleaned the MAF, checked the filter and its not over oiled (I used K&N my entire life and know the drill with oil and MAF's), checked all vacuum lines and they are all good. Cleaned the throttle body and put it all back together. Drove over 200 miles no issues. Wife gets in to drive me home one night, within 10miles, threw the P0101 code. I pulled everything apart again, cleaned everything again and this time cleaned out the air filter and oiled it very lightly (less than what I'd normally use), let the filter dry in the sun for an entire day and popped it back in.

I got 257 miles, no codes. Wife drives it, again, within 10 miles it throws a code. Every time it throws a code its when she is on the freeway. Never throws a code for me on the streets or freeway.

I spoke to the dealer and they said next time it throws the code to bring it in with the code on so they can scan it. I brought up the TRD intake being a possible issue and they said 'we have installed 100's of these on trucks and never had one come back throwing codes".

So can anyone think of why its throwing codes right away when my wife drives it? (besides saying my truck hates my wife). I know these ECU's 'learn' the driver. Could this be that I need to not let her drive it for a couple of tanks of gas so it learns how I drive? Any suggestions on this? I'm not going back to stock just yet, and I've talked to a hand full of people who have ran the second gen TRD intake for years and never once had an issue. The first code was thrown leaving the dealership, what could they have done during an oil change to F that up? (they didn't clean filter during oil change per my request).

 

Might want to try the URD MAF Calibrator.

Oh and, your truck hates your wife

 

LOL! I'm reading up on the URD MAF calibrator now to see if that's going to fix the issues.

One thing that I forgot to add, my AFR and as MAF readings are not changing/dropping/increasing at all once the code hits. The numbers are constant all the time.

 

Only think I can think of is your wife's driving habits might be more aggressive than yours. I'm not an expert on any of this stuff but have read plenty of threads where people claim turbulent air across the MAF sensor can throw a code. URD's calibrator fixes the issue somehow.

 

@pugga: I'm pretty sure its the other way around. I avg about 18mpg in my truck, my wife gets 22 out of it. She drives it like a grandma, I drive mine like the cops are chasing me. I'm still looking at the URD calibrator, just an expensive fix for a problem that shouldn't be happening.

Ah didn't know about the fix on youtube I'll have to look for it, thanks Whipper.

Is this what you are referring to? I'll cut it tonight and find out for sure.

http://www.youtube.com/watch?v=TfMpeTdseMU


EDIT: What is the Air/fuel ration number I am trying to hit? I never paid attention to what it was stock.

 

The intake tubing covering the vacuum ports isn't my issue. My TRD intake doesn't cover those at all in anyway.

Did some runs while recording AFR data.

AVG idol: 14.8
AVG WOT: 12.9
AVG Freeway: 13.9

Every once and awhile during idol it jumps up to 15.2 but drops down pretty quick again to 14.8.

 

The AFR that you refer to is your air to fuel ratio and it is a calculation that tells how efficient your engine is. This is also known as your Stoichiometric ratio, and should be 14.7 : 1 . This is your ideal ratio to provide the most power from your engine, and it is a compromise between engine performance and economy and low emissions.

As for you MAF, to me it sounds like the internal heater for the wire is failing and the MAF is freezing up do to the cold air from interstate driving. The velocity of the air going into the MAF determines the cooling of a little wire that is heated to provide a constant index number. It is the amount of time that the sensor changes temperature tells the main computer what the temperature of the air is.

You need to check all your connections for air leaks that are occuring after the MAF sensor. You could be letting in too much air for the engine to compensate for. Does your engine drive badly or surge or lose gas mileage ? If all your connections are good, you could check the MAF. A preliminary check is to disconnect the wires to the MAF and see if it runs better. It will throw a code, but see how it runs with it disconnected.

If you can see your Short term fuel trim and your long term fuel trim with your scan tools. If the Long term fuel trim is in the positive ( above 10% ) and the short term fuel trim is in the negative range, the MAF could be bad. If they don't look bad, then check the MAF reading at idle. It should be reading a number in pounds per minute or Grams per minute. It should read from 3 to 6 grams per minute or GPM. Then slightly open the throttle and read the number, it should rise as you open the throttle. If the number jumps quickly or does not move then the MAF could be bad.

You can also tap the sensor with your finger while it is idling and see if it stumbles. Also a restricted exhaust will cause MAF problems also. Check the wires on the MAF to see if they are frayed. GOOD LUCK

 

Thank you for all the info! I want to go over a few things from your post.

As for the MAF cooling, its possible but it's pretty hot here in AZ. Air intake temp was reporting 89 degrees while being 88 outside when it last threw a code. I had came home from work and we left about 30 min later, truck was parked outside in the sun.

- I pulled apart everything and cleaned again (got a dry filter from autozone that fits the TRD intake to make sure oil isn't an issue- no changes at all in AFR readings due to this)
- replaced the vacuum lines just to be safe
- Checked for any other leaks, all looks good. The truck is only 6 months old, I'm first owner.
- Checked the wires to the MAF to make sure nothing was loose/frayed all look spiffy.
- Logged short term and long term fuel trim, all numbers seem ok and are not dipping into negative numbers. I set it to read GPM, at Idol was getting around 4, as I open the throttle the number raises and declines with the throttle.
- Tried tapping my sensor, no change
- took the MAF off my Dad's taco, cleaned it and am running that now while logging data to see what happens.


When you are saying the AFR should be 14.7:1 is this during Idol or WOT?

I also found that I have 2 sensors for AFR, Command and Measured. These are never matching when at a stead speed, and are always off by about .2/.3 (Say command reads 14.7, Measured will be 14.9; measured is always leaner then command). I haven't looked up what means, my guess is command is what the ECU wants and Measured is what I'm getting.

 

You are doing a good job with your looking for a answer. Yes , 14.7 to 1 is the perfect and ideal measurement of your air to fuel ratio to give you the best power with best economy and emissions. This should happen at idle and at almost all power settings. It may vary a little during acceleration, but it will settle back to Stoic.
The command measurement vs the actual is a great number to be able to see. You will see what the ECM or computer wants and what the actual number is. If those numbers are not too far apart, you have a good sensor. I think that .2 to .3 is not too much to be off in the settings.

It is great that you can substitute another MAF for your original. If you can keep it a while and see if you can make it throw a code. This will help you find what is wrong if the MAF is good.

As far as air cooling, even though the outside temp may be near 90 with air coming down the tube and going into a narrow opening, the air may be 30 degrees cooler going by the MAF.

How did you check your air tubes for leaks, if you have it, you need to take some intake cleaner and run your engine at idle and spray around your connections and vacuum lines. If you get a stumble from doing this then you may have a air leak there. If you do not have any intake cleaner, if you have a small propane torch, you can slightly crack the opening and hold it around your connections and see if the idle goes up. If it goes up, you have a air leak.

I don't know how long you can use your father's MAF, but if you do not throw a code in a couple of days. That may be your problem. GOOD LUCK.

 

Interesting tips! Thank you.

I can run my dads MAF as long as I need, so I plan on running it for at least 2-3 weeks to see what happens in both trucks. His truck throws a code I know what the issues is.

As for checking for leaks in my air tubes I pulled them off one by one, clamped the very tip off, put them in water and ran low psi air from my compressor, no bubbles. Did about 10-15psi without any leaks. Then took them out, sprayed them with air to help them dry out just in case water got in there, then let them sit in the sun for about an hour. When I reconnected them I just did what you said with intake cleaner and sprayed around the connections while the engine was running, again, no leaks that I could see.

I'm still sure this code is from the design of the second gen intake. I'm more so now just having fun trying to read all this data and figure out what makes it throw the code. I do appreciate the help you have dished out to me. I'm learning a ton about my truck this way.

 

So I threw a code last night, same P0101 using my Dad's MAF from his truck. Ruling that out now and taking it to the dealer to see what bullshit they try and feed me.

I got a chance to look at the data, and it looks like the code threw when I was getting on the freeway very gently and accelerating slow. I got up to 65, hit cruise, 2 seconds later the code threw. So it seems that if I do not drive my truck pretty hard, it throws a code.

What I was thinking about trying to do is pull the battery cables off, let it sit for an hour, then drive it like a granny for 2-3 full tanks of gas. When I bought my truck I let it 'break in' for the first 1500 miles. Nothing over 45mph, and lowest RPM's that I could. The intake was put on at 102 miles and never threw a code regardless of who drove it all the way up to when I had the dealer do the first oil change. Maybe I need to have the truck learn my driving style as very calm for awhile, then go back to my normal driving habits.

 

I am sorry that your problem has returned. Can you put your intake back to stock? I know it isn't a solution, but since you first wrote that you had no problems, till you had someone change your oil and it is still happening. I think that there is something not right in your system. Maybe by returning it to stock and see if any more codes come, since you now know how to trigger the code. If no code comes, then there may a problem you can't see or find in your intake.
If you can re trigger the code with stock intake back on and the MAF is good, then it is a problem with the PCM or computer that may be triggering the code. I wish there was a simpler way, but this is a uncommon problem and you need to rule out what is or isn't working correctly.
Good Luck.

 

Are you sure you have the MAF installed in the correct manner for flow? I've seen people install them backwards I have a 2011 and a TRD intake and have never had any issues in 20K miles.

 

Thanks guys!

Yes the MAF is installed the right way. And I can put it back to stock and will have to try that. I still want to see what the dealer since I did put over 4,000 miles with out issues till they touched it. I'm waiting for a call back from them to see if they just want me to bring it in or bring it in when the code throws.

 

So I took it in when the code popped up again. They ran tests and replaced the MAF and the wiring to the MAF sensor. Hopefully this fixes it.

 

Thank you!

Yes its been a real pain in the ass. But the Torque app has really helped me in proving to them that the intake isn't the issue. I've been logging a set amount of sensors and putting them into text files and also having Torque twitter all my sensor data as I drive. So the tech at Toyota was able to read all of this data, compare it to his machine data and also agreed that the intake doesn't seem to be a problem. We found that under very mild acceleration around 50-60 (say getting up to freeway speeds like a grandma) for some reason my AFR would drop around -23.23 (at least that's what the sensor was logging). When we checked the MAF readings at the same time the AFR dropped and the MAF was reading was showing as .01 (normally its 14 when cruising around on the freeway). I ran a different MAF and had the same issues, Toyota replaced the harness and MAF to make sure. Now its just a waiting game to see if it really is fixed.

 

These kind of code setting problems can usually be resolved by locating whatever is allowing air to bypass the MAF sensor. If you have access to a smoke machine id suggest smoking the system. I use a smoke machine to find the tinyest leaks all the time at work.

BTW Im glad no one was injured by all the codes that were being "thrown" all over the place in your truck. At least your truck is concerned with basic hygene and not "spitting" codes at you. Those ECM's can be down right rude at times. Well mannered ECM's "SET" codes. LOL good Luck

 

After the dealer replaced the MAF and wiring harness for it, I got another Check engine light. Same exact code. Weird thing was I went to the bank, got out and got back in my truck within 5 min, check engine light was off. Let the dealer know and they suggested to pull the battery cables off to reset the ECU. Giving that a shot, if not back to the dealer I go.

 

This same exact thing has been happening to me lately. I have a TRD air intake and TRD exhaust. My check engine light has been coming on and off for about 3000 miles now. The first time it happened I disconnected the battery for about 5 minutes and the light went out. So, I thought good to go but it is still happening the truck does not drive any different??? anyone else

 

just installed my trd intake ;good so far. but ill be watching. i gota get my scan tool up dating but snapon is so proud of their stuff