DIY: MAF, Throttle Body and EGR Cleaning Write Up

Ok so decided to take a look at my MAF and Throttle Body, the MAF looked great but sprayed it down anyway, the Throttle Body was filthy so I decided to clean it and the EGR while I was at it.

Note: Did not have my low tech pointer so had to draw circles on the pics.

Note 2: This may seem like a daunting task but it took me about 30 minutes and I would not consider myself a master mechanic of any sort. I did notice a significant boost in performance as the Throttle Body and EGR were very filthy.

MAF (Mass Airflow Sensor) Cleaning:

Step 1: Locate MAF. See pic below, its the unit on the back of the hose between the air intake filter box and the intake manifold.



Step 2: Remove connector. Pretty easy to pop right out.



Step 3: Remove 2 philips head screws.



Step 4: Carefully pull out MAF and spray down with approved spray. I recommend a MAF cleaner or other electronic safe spray.







Step 5: Reverse steps to re-install. DON'T drop the sensor!!

Throttle Body Cleaning:

Step 1: Remove Air Intake Hose. Loosen hose clamps with 10 mm socket.



Step 2: Remove Throttle Body by removing qty 4, 10 mm bolts. DO NOT REMOVE HOSES GOING TO THROTTLE BODY!! THESE HOSES CARRY COOLANT. TRUST ME.



Step 3: Using a brake cleaner or other fluid, clean the throttle body and butterfly valve. Make sure to get the ends of the valve as this is what props open the valve over time causing a mis-read of zero-location position.


(Side 1 above and partially cleaned side 2 below, dirtier on side 2 b/c of EGR system)


Step 4: If you're going to clean the EGR, leave Throttle Body off. The truck will eventually re-program Throttle Body position but for more instant effect, remove battery cable to let computer reset. Warning: this will reset your radio favorites and all synced devices.

EGR (Exhaust Gas Recirculation) Cleaning:

Step 1: Locate EGR Valve. See pic below, this is it (the one with the silver hard line going into it. Again DO NOT REMOVE HOSES!! These are the same coolant circuit.





Step 2: Free EGR valve by removing top hardline, then lower hardline and 3 bolts on EGR valve bracket. Will need a 10mm and 12 mm socket for this. Will need a 12 mm wrench as one bolt is hard to get to and not enough space for a socket. (previous picture shown)

Step 3: Clean hard lines, EGR valve (both spaces), let enough time to pass for cleaner to evaporate as you don't want this injected into your engine on startup. Also clean flanges.







Final Step: Re-assemble everything. It is normal that first engine crank will not start truck since pressure in EGR and intake system is lost. Should crank on #2 try.

Second Final Step: Take a badass pic of your Tundra (See below, 112k miles, 100% stock and proud)

 

Excellent write up. How often do you perform the cleaning? I am at 50k now. Thanks

 

It's the first time I did it, I wish I had done it at 50k intervals, there was some solid carbon deposits that fell out of some of the pipes.

 

Nice work. By the way we use CRC here at work. Good stuff.

 

Thanks for the detailed description and pics. I'll be doing this when the 100 degree weather subsides.

 

Thanks. I guess I have some work to do on my Tundra.

 

Fantastic write-up! On the to-do list!

 

oh nooooooooooo

Great write up. thanks !

 

If I may suggest, maybe add in the OP that this is for the 4.6L engine. The 5.7L doesn't have EGR.

 

Definitely on the to do list. What did you use to clean the EGR?

 

The 5.7 sure does have EGR. May not look identical. It it's there and can be cleaned the same way. I can post the instructions for that later

 

Used carb cleaner for the EGR

 

Maybe my Google-Fu is not working today, I can't find anything on it. I was thinking of doing this today, but not being able to find anything has gotten me sidetracked. I await your findings.

 

Would one of or both of these work for all 3 jobs?

 

Sir you are correct, its not an EGR persay on the 5.7 but it there is a canister that injects hot gasses just downstream of the Throttle Body just like a convenstional EGR. If you'd like instructions for that I can get them to you but I imagine it will not be near as dirty.

Get both. Don't use the carb cleaner on the MAF, and the MAF cleaner may not be strong enough to clean the EGR valve.

 

Huh, I wonder what they're calling that then. I suppose that if they're not "exhaust" gases, it's not technically EGR, as you mention. Well, if you have some information on it, I would be interested in reading and hopefully learning about it. If you have access to it, I'd be obliged if you'd be able to share it. At your leisure of course. Thanks!

 

Not much on it but this is what I could find. Parts locations. Looks like there's an air injection spot on the back of your engine.

 

Is yours a 4x4? I ask because I'm looking at upgrading to a 5.7L 4x4. My question is does it seem slugish to you compared to a 2WD? I test drove a 4x4 once with a 5.7 and it seemed heavier and slower than my 4.6 2wd.

Edit: Previously i've driven my father in law's 5.7L and it seemed quick as hell but it was also a 2WD.

 

Boy you were right, there isn't much there....

I've never driven a 2WD, so I don't have a reference. There isn't much use for them here. Pretty unusual to even see one. The only real difference that I can think of would be the in the weight of the front drive. Maybe another thing would be the final drive ratio, but I think that +90% of the 5.7Ls have the tow package and the lowest (4.30) gearing. Unless you tested a 4x4 5.7L that didn't by mere chance.

My truck is a RCSB, it's quick. In theory, the only potentially faster configuration would be a RCSB 2WD. In stock form.

 

I just did the MAF, TB and EGR cleaning......the tutorial was spot on!

The MAF was not really dirty but the TB, EGR and hard pipes were full of crud.

Thanks,
Ken

 

I know this is an older thread, but CRC recommends using their 'MAF Sensor Cleaner' now for the Mass Airflow Sensor. Claiming it is safe for plastics and residue free.

 

Is this a 5.7 2007 tundra ??? I do not have a egr valve like that. I’m having misfire issues

 

This is an older thread but the best explanation of how to do all theee of these things. Thank you for the pictures too. I have a 2008 Double cab Limited with 230K miles. It is still running strong and I’ve been doing my own maintenance the last year or so. Thanks!

 

Not phillips, JIS

 

My 2011 4x4 5.7 has an oil-able type TRD air filter, and occasionally I get a Check Engine light, and code for MAF sensor. I do a quick clean with CRC MAF cleaner, and it clears the code. (I also disconnect and clean battery terminals). I never see any dirt in or on the sensor. Also, the CarNut on YouTube has a video on cleaning the Throttle Body, which does get dirty.