GMC Yukon P0121 code fix and throttle body cleaning

Cleaning the throttle body and fixing P0121 code. Includes idle relearn instructions. Chevy, GMC, Sierra, Suburban, Denali, Escalade. 2007-2013

[@2007jdp]

This is a great video. Couldn't have figured out ot fix problem without this video.

[@trevorwindhorst5779]

Thanks for sharing! This was exactly what my Yukon needed. Pick-up on throttle and response has improved greatly! I suspect towing my 21' foot boat will be more back to what it used to be now. Shocked at how dirty that throttle housing was! Easy to follow instructions and worked great! I tried the run for 3 minutes and shut it off for a minute several times and it still idled high so I took it for the recommended 50 mile drive on the freeway, came back home, turned the engine off and restarted it after a couple of minutes and the idle seems to be working great now. Thanks again for sharing!

[@trevorwindhorst5779]

I should mention that I didn't take the throttle body sensor off. I was a little chicken to do that and afraid I wouldn't be able to get to work in the morning if I messed the sensor up too bad. I just cleaned the interior of the throttle body very thoroughly, stuffing a rag down inside a little to keep the brake cleaner fluid out and used an old tooth brush and several rags to clean, spraying the brake cleaner directly onto the rags I was using and then wiping and using the tooth brush to clean the interior.

[@torresbpxlife]

Best video out there, well explained sir. Very informative step by step.👍

[@robertedwards1364]

Well done video.....very informative and good camera work. I hope I don't mess things up.

[@elflacoperez6252]

Thanks for all the help and support 👍👍

[@Adam-dz2so]

Great video, THANKS! After cleaning P0121 has disappeared!!!

[@mcdingus9840]

Great video. Fixed my check engine light 💡

[@mikebas7325]

Big thanks to the in depth explanation. I have done this type of cleaning on a few cars but none of them had to relearn their idle. My 07 Escalade did not relearn the easy way of the 3 minute run times, I had to drive mine several times. I have been driving it on/off for the last week and it seems to be getting better as well as the engine light going off by itself. Thanks again.

[@christopheremanuel5063]

I know it's quite off topic but does anyone know a good place to watch newly released series online ?

[@drewsam6387]

@Christopher Emanuel Flixportal

[@christopheremanuel5063]

@Drew Sam thanks, I went there and it seems like they got a lot of movies there =) I really appreciate it !!

[@drewsam6387]

@Christopher Emanuel You are welcome :D

[@SladeWilsonOG]

Brother your help is appreciated On a side note i left my throttle body connected while I cleaned it with carb cleaner and no reset was needed and I got all my throttle response back thanks again bro

[@adrianquintana6086]

Thanks this really help me alot

[@catherineharris4746]

Outstanding! Thanks!👍👍

[@haleiwahi27]

This is a great video for beginners. I like to critique these videos since I feel everybody benefits on making better videos. The only thing I would add is why or why not to actually remove the TP sensor, explain what's behind the sensor so that way curious kids doing this for the first time would know what to fear or what not to fear. You might even explain a little about the throttle motor behind the sensor. Again great video as far as it went.

[@fungdark8270]

And maybe inject some anti-electronic sentiment 🤣 With a cable driven throttle, this wouldn’t be an issue beyond cleaning a dirty throttle plate.

[@alejandropascual1973]

Thanks a lot good explanation!

[@jesuspena4439]

good video

[@Beardeddad0108]

Hey your car guy thank you for this video really appreciate it I’m no where near up to speed on auto mechanics I have 2006 GMC Yukon Denali 6.2 let engine service stabilitrak went off then went off after parking vehicle for a few hours but today noticed a slight hesitation after going to put it in drive as if it didn’t want to go anywhere often also can feel a hesitation thinking maybe because of ac but really not sure any idea what could be?

[@Beardeddad0108]

Correction 2007**

[@YourCarGuyDR]

Jason Haines so the stabilitrack can cause loss of power as it has the ability to cut power or apply brakes. If one of the sensors is bad or out of calibration it can be an issue. You probably need to have it scanned with a code reader that can read the stabilitrack in order to determine where to start. There are several sensors that can cause the issue you are describing.

[@rubbermallet3873]

check ur motor mounts 💤

[@rubbermallet3873]

👌thanks boss 🤠👍

[@melissascott8132]

Thanks 😊

[@archiecunningham3734]

Thanks!👍🏻

[@mrbrandonamyers]

Thank you for the Video. I have a 2009 Suburban I took the throttle body off and it was pretty pretty dirty. I can now feel a significant power increase. Is that normal?

[@YourCarGuyDR]

Brandon Myers yes it is. Clean means more air is able to flow which in turn means more fuel can be injected and still achieve the proper air fuel ratio which equals more power.

[@Toys4Life]

I think it is the placebo effect. This cleaning is only going to affect the idle. The minimal buildup is not going to equal any more airflow at wide open throttle.

[@fungdark8270]

Toys4Life C5 Idk, a dirty plate tha is leaking more air at idle would maybe mess with fuel mix to compensate? Having a proper idle for the computer to work of may help the entire rom range of the engine?

[@ahmodad9252]

Is that an MHC logo on that uniform?

[@Toys4Life]

The re-learn process may take a while so do not do this on Sunday night for your wife and think she is going to be in rush hour at 8AM Monday morning. Also, HP tuners helps re-learn the idle if you have that available to you or know someone who does - without having to buy any credits.

[@isaiah-lava5.086]

It doesn't show it on my 03 something else i can do?

[@nathanduckeorth806]

I tried to reset that high idle speed using the procedure you mentioned starting it up and shutting it off and drove it with no avail! Finally had to call a buddy to stop by with his box that he plugged into the computer to reset the idle using modern technology! Took a couple trays but he got it! It was a bitch! Never touch it again lol

[@YourCarGuyDR]

It will reset itself after a couple days of driving if you don’t have a computer that can do it.

[@ericpigg2689]

My exact same experience on 2012 Yukon. The manual re-learn never worked for mine. It had wild high idle in P or N and when it was in gear, it would accelerate automatically after you let off the brake with no gas pedal input. I also drove it over 150 miles over a few days with no change. I am like you, no more messing with throttle bodies. I am a shade tree guy, and lack the $3000 programmer needed to complete this job properly.

[@jeffilli1663]

I have the same code on my GMC canyon 2009 175,000 miles. Mechanic told me i need a whole new throttle body assembly just from looking at the code and not even popping the hood...

[@YourCarGuyDR]

jeff illi get a new mechanic.

[@carlosolmedo2529]

I got a 2007 esclsde it accelerates I'm park when I switch it to drive and press the gas pedal all the way down it moves forward but at a super slow pace , it will gain speed just real slow , any idea

[@YourCarGuyDR]

Is your engine light on? There are quite a few things that can cause your issue. Check for codes first.

[@tracywood2841]

Hey Your Car Guy DR, I have a GMC Yukon XL, 08. I am getting the check engine light, Autozone says the code is this sensor. What size tool-wratchet did you use? I want to be prepared.

[@tracywood2841]

And, one mechanic said nobody replaces the sensor anymore because the issue is most commonly the entire throttle body. Do you agree? I an seeing the sensor online for $40, the entire throttle body for $87, so which should I go with?

[@YourCarGuyDR]

TRACY WOOD I recommend the entire body. Just be ready to go through the relearn procedure. A standard set of metric sockets will have what you need.

[@StyleOverPolitics]

Im trying to clean my throttle body but my mechanic said dont mess with the flap while cleaning but i noticed you were opening the flaps closing it etc, doesnt that ruin the throttle body?

[@YourCarGuyDR]

It won’t hurt it at all.

[@asimsaif2888]

هل هناك مقطع مترجم؟

[@coolrabbit75]

I did all that and my car ran great all day then I started getting that reduce engine display again but I noticed some brown gunk in my pc hose it a 2014 Chevy equinox

[@YourCarGuyDR]

charles moore the brown gunk in the pic hose is usually normal. Did the check engine light come back on and if so what code did it give you?

[@coolrabbit75]

@@YourCarGuyDR the reduced engine light has been coming on

[@YourCarGuyDR]

charles moore have you had the codes checked?

[@coolrabbit75]

@@YourCarGuyDR pto013 camshaft position actuator output

[@YourCarGuyDR]

charles moore there is a good chance that the camshaft position solenoid is bad and needs to be replaced. Not a very difficult job and you can find the solenoid online for very reasonable prices. Remember that with variable cam motors that not changing your oil on time can cause performance issues.

[@victorescudero8029]

Car Guy, I changed the TP sensor as I had an internal connector loose, and cleaned out the throttle body. However, the code came back... I was told that it could be the pots on the pedal itself. Any insights and/or suggestions ?

[@YourCarGuyDR]

Victor Escudero it is possibly to be the pedal but I would check the wiring that runs from the tps on the passenger side of the engine

[@victorescudero8029]

@@YourCarGuyDR - will do. Thx. - I took the Yukon for a drive and matters just became much worse, it is surging badly and the transmission dis-engaged going into Safe Mode... had to stop several times to disconnect the battery, reset and get going again... but something is very wrong with TPS circuit making the engine and thus tranny go crazy. I will check the wiring, anything else comes to mind ?

[@victorescudero8029]

@@YourCarGuyDR - Thx. I will check the wiring. FYI... took the Yukon for a drive and matters got much worse. It began to surge pretty badly to the point that the transmission dis-engaged going into Safe Mode. Had to stop, turn off and back on, until I was able to get off the road, disconnect battery - reset and go again, only to repeat 5 minutes later... had to do this several times until I got home... I will check wiring, but anything else comes to mind ?

[@YourCarGuyDR]

Victor Escudero usually when this happens it is a wiring issue. Make sure your throttle body is calibrated as that will cause some idle and surging issues. It will calibrate itself over the course of a few days driving or try the calibration process.

[@victorescudero8029]

@@YourCarGuyDR - Thank you, keep you posted.

[@franciscoayon9470]

Excuse me,how would ik if it did the relearn,I did everything but also unplug the baterry,I reconnected everything back,turn the car on and off 2 times,rpm are around 600,before it was more around 800

[@YourCarGuyDR]

If you can’t get the relearn process to work just drive the vehicle more. Each day you drive it will get better and relearn itself.

[@azamshahzad7722]

I cleaned throttle body 2006 escalade with "acdelo carburetor tune-up conditioner" even did not remove the throttle body, but after there is some problem in engine speed, accelerate by it self. can change the throttle body or wait 1 week. please advise ?

[@YourCarGuyDR]

Azam Shahzad the throttle body has to relearn the new position after cleaning. It will tend to have a very high idle until it relearns. No need to replace the throttle body.

[@azamshahzad7722]

@@YourCarGuyDR thanks for yr reply you save my money, what time it will take for proper working. also, my Cadalic is over heating today even coolant is okay. In my Cadalic there is 2 small fans not a big fan which I saw in some Cadalic , is this thermostat problem?

[@YourCarGuyDR]

Azam Shahzad if the fans are running then I would look to change the thermostat.

[@Nunya412]

Hey cleaned out my throttle body now it’s idle very high 2/3 going up to 40km without gas lol any solution or ideas to get back to normal

[@YourCarGuyDR]

I see Fake ppl if you have a friend with a scanner that can do a throttle reset it will fix it. Otherwise just keep driving it and it will adjust itself after about a week of normal driving.

[@justinramirez2494]

@@YourCarGuyDR i cleaned my throttle body and now my car is idling @ 3000rpm. I tried the 3mins on 1 min off about 10 times. Stayed @ 3000rpm. I tried to put it in drive and it wouldn't move. Have you heard of this before?

[@YourCarGuyDR]

@@justinramirez2494 I haven’t heard of the truck not moving. Usually if you drive the vehicle for several days it will relearn the idle position and go back to normal. If not find someone who has a scanner that can do idle relearn.

[@illustr8phee100]

I got 07 escalade 180,00 should I trans flush? or just filter an Fluid?

[@YourCarGuyDR]

Illustr8 Phee just filter and fluid.

[@reneeaw710]

Hi, thank you for posting this video. I have a 2008 cadillac escalade and everything seemed to match up, but I'm having trouble getting the part loose at the 1:13 - 1:23 minutes. I'm not feeling a rubber part when i put my hand under to hold it/loosen it. Any suggestions? Thanks

[@YourCarGuyDR]

reneeaw710 yes just pull that strait up and it should release.

[@reneeaw710]

Your Car Guy DR thanks for the prompt reply! I'll give it a try.

[@cccasse1s629]

How do I find the part number for a original throttle body (2008 Yukon 5.3) so I can order the part online?

[@YourCarGuyDR]

cccasse1s usually you can go to one of the dealer websites and look up the part and get the number.

[@locklearoutlawscl21]

Does it knock when In limp mode like the lifter knocking when the throttle body goes bad

[@YourCarGuyDR]

You should not have knocking in limp mode.

[@pourtierbeatz7804]

By replace the sensor you mean the black portion on the throttle body? I dont think they sell that portion seperate its usually a complete throttle body they sell it

[@YourCarGuyDR]

You are correct they usually sell you the complete throttle body.

[@ericpigg2689]

You can buy just the throttle position sensor. I did it last weekend for my wife's 2012 Yukon.

[@KevinMcWhorter]

I think my code has something to do with my recent cleaning of my K&N filter. I probably applied too much oil. I also didn’t wait long enough for it to dry. That’s my guess.

[@YourCarGuyDR]

It could be.

[@mizzperez91503]

Hello can someone help me please. I replaced the throttle body and the idle is yet to relearn itself. I’ve been doing the procedures as explained in the video. The issue now is that I got a new code P0300. Is it normal to have this code while it is relearning?

[@YourCarGuyDR]

The p0300 is not normally associated with a throttle relearn. It means that the engine computer has identified a misfire. Depending on how long it has been since replacing spark plugs it could simply need a tuneup. It could also be a bad ignition coil. I would clear the code and drive it a few days. The idle should relearn itself over the course of several days. If after the idle returns to normal you still get a p0300 code then I would begin investigating that.

[@Lifeofrobbie84]

So when lose pressure on the gas paddle this is the problem my 04 wont pick any speed pass 10 miles a hour

[@YourCarGuyDR]

Hood Shaman you may have a bad pedal, a wiring short, bad tps, or blown fuse. The default when the electronic throttle is usually around 10mph when no signal is received. It would be good to check your code first to verify what you need to check.

[@Lifeofrobbie84]

@@YourCarGuyDR thank u

[@YourCarGuyDR]

Hood Shaman if you don’t have a way to check your codes try unplugging the connection at the tps and plugging it back in. Do the same at the throttle pedal. If the throttle pedal is not returning to its normal position or has no resistance then it is likely a bad throttle pedal.

[@clemsonsteeler-man9803]

Hey buddy, i have a 2007 yukon Denali and i have to code to replace my throttle body, but my mechanic said that he will have to buy a upgrade from GMC and that will cost to purchase that program. I can replace my own throttle body what i would like to know is would i have to download some software, or is the relearn the software that my mechanic is talking about. Thanks in advance for all your help.

[@YourCarGuyDR]

Brian Porterfield the vehicle will relearn the throttle body position it just takes some time. Generally if you drive it for a week or so it learns it. The idle will generally start high. There is a relearn procedure that you can do without software. Sometimes it doesn’t work and you just have to put in the miles while it relearns.

[@alfredobeltran7787]

So I replaced the sensor and now my truck accelerates by it self I left it on for 3 minutes then cut it off .. & then took on a drive then it was good but then I put it on park and it started to accelerate by it self again.. so every time I put it in reverse or drive it comes back to normal but then I cut the engine off and it starts to accelerate by it self

[@YourCarGuyDR]

Alfredo Beltran more drive time will fix it. Mine was similar until I drove it for several days. After about 1 week of driving it was normal. I did the reset procedure several times and it got better but the computer still required plenty of driving to readjust.

[@alfredobeltran7787]

Your Car Guy DR right ima try that and see what happens ... do you think I probably got to reset anything in the computer or something?

[@YourCarGuyDR]

Alfredo Beltran the dealer has the ability to do an idle relearn with the computer. The computer will relearn the position by itself but it takes a few days of driving.

[@robertotrevizo9981]

Hello I have the same problem with my tahoe you say need drive the car and this work fine later ?

[@MrJar1rad]

Didn't have any problems with my truck but after I clean the throttle it starts then it shuts off after 4 seconds everytime.... need help

[@YourCarGuyDR]

Jarrad Judah check your intake air connections. If you have a vacuum leak after the mass air sensor it can cause exactly what you are describing.

[@user-um6sx6yw6p]

Hi sir. After cleaning I got message energy is reduced and accelator pedal is not working

[@YourCarGuyDR]

truthhh try unplugging the throttle body. Inspect the pins in the wiring connector for any corrosion or bent pins. Then plug it back in and check it. You can also unplug your battery for about 15 minutes if that doesn’t work. Make sure you have the key off when you do these.

[@user-um6sx6yw6p]

@@YourCarGuyDR Thanks sir

[@luigegonzalez7399]

Hey man i have a 07 Denali got a code for the throttle p0121 truck would hesitate as it wants to shut off but doesn’t only in complete stops it does it cleaned it did relearn several times drove it for about an hour and half dropped from 2,000 to 500 rpms now but still does the same while at complete stops took a bit to drop to 500 rpm and it is still kind of accelerated while stopping ? Any suggestions don’t want to get stuck somewhere think it needs replacing?

[@YourCarGuyDR]

Luige Gonzalez it can take several days for the relearn to complete. During that time the idle and rpms will be a bit erratic. For the shutting down check the wiring going back along the valve cover. You may have a rub. More importantly make sure you don’t have a vacuum leak between the mass air sensor at the air filter box and the throttle body. Leaks in that stretch will cause shutdown at idle because the computer isn’t sensing as much air as is coming in and it will reduce the amount of fuel to the engine causing a shutdown.

[@luigegonzalez7399]

Your Car Guy DR thanks man really appreciate the feedback !

[@ravennight6744]

I dnt have Denali but it looks the exact same under hood except the engine cover is that important to have on your car. Also the hoses were so brittle they were disintegrating I covered the words with electrical tape now I hear thats not good I haven't drove it yet.. now I'm see mixed reviews is the electrical tape really bad will the engine get over the 220segrees.. will it melt my wires or what?? Any comments appreciated.

[@YourCarGuyDR]

Electrical tape is much better that broken loom. Parts of the engine will run over 200 but it shouldn’t be an issue for now.

[@malvinprater6225]

Why my 2010 Denali reduced power it want go over 15mph

[@YourCarGuyDR]

It may be in a default mode if your tps sensor or throttle pedal sensor is not reading correctly or has failed.

[@CUATE31NAYARIT]

I clean it and everything but the idle is still high does not relearn. Rpm at 2 then keeps going up to 3. I have a 2007 Chevy avalanche. I ordered a whole new throttle body with sensor just waiting for arrival. Will that be better off

[@YourCarGuyDR]

NAYARIT31 sometimes the relearn can take up to a week of driving. The other option is to have it reprogrammed by someone with a scanner that has the programming ability. Most likely the new throttle body will have to be programmed.

[@rahrah8076]

NAYARIT31 find someone that has a scan tool that can do a idle learn reset

[@MrFrankier27]

If I buy a new one do I still have to re program it

[@YourCarGuyDR]

A new one will still need to go through the relearn procedure. This can be done either via scanner or through the relearn process.

[@MrFrankier27]

Bought a new one tried re programming it but still have the check engine and idles a little high

[@YourCarGuyDR]

@@MrFrankier27 the idle should adjust itself over about a week of normal driving without programming. Check your wiring and codes to make sure that you don’t have a loose connection or rubbed wire.

[@MrFrankier27]

I was driving it right now for like 20-30 min it works fine when on the freeway as I come off the freeway to a stop light it idles up down up down then it stay normal idle till I go again , I checked my wiring and connectors they all seem good

[@YourCarGuyDR]

@@MrFrankier27 the up and down idle should improve over a week of driving. If not look for a vacuum leak.

[@javierjavier7291]

What was wrong with an accelerator cable

[@YourCarGuyDR]

The advent of electronic throttle has allowed many of the safety and stability systems to exercise greater control over the engine. The ABS and Stability Control can override the pedal throttle input when those systems feel it is necessary for safety. It can be very frustrating.

[@daddysoulmanrich]

You dont.need to take.off throttle body and it will re learn itself

[@YourCarGuyDR]

daddysoulmanrich you are correct on both counts.

[@jasonmaddox8913]

NEVER PUSH THE BUTTERFLY OPEN !!!!🤦‍♂️

[@gregmerchant561]

Are you going explain why??

[@jasonmaddox8913]

greg merchant because it's not meant to be, the throttle is set by the computer and you're liable to throw it out of whack

[@fungdark8270]

Electric motor lmao

[@YourCarGuyDR]

Fung Dark your comment made me smile. Thank you.