Nissan throttle bodies are notorious for getting dirty pretty quickly. If your car has issues with the RPM dropping at idle, it is probably a dirty TB.

Items Required:
- 8mm socket wrench
- 10mm socket wrench
- 5mm allen key
- Clean towel/rag
- Throttle body cleaner
- Pliers (optional)
- 2x throttle body o-ring seal (optional)

You will need to have the engine cool down before you start working. First you'll need to remove the engine cover. If you have a FSB like me, you'll need to remove that first. Simply take off the aluminum bar with the required allen key.




Next you'll need to remove both intakes to access the throttle bodies. It is best to clean one TB at a time. Removing the intakes will depend on what type you have installed.




Once you have removed your intake, you can see the TB and the butterfly valve inside (golden). You shouldn't see much dirt yet, as most of it loads up behind the valve. To take off the TB, you'll need to remove four hex bolts as shown below with a 5mm allen key. use the star configuration when removing and installing these bolts. They will be tight since they have thread lock applied to them.




Once you have removed these bolts, take care when pulling off the TB since there is an o-ring seal on the plenum. The TB will also have a connector for the throttle position sensor as well as two tubes connected to it. DO NOT disconnect the harness connector or any of the tubes. You should have enough space to work with. If you do, the ECU will not recognise idle throttle position and will cause the car to idle and run poorly.




You can see all the dirt on the other side of the TB. It is really sticky tar and will need some nice scrubbing with a towel and a TB cleaner to remove it.




There will also be some carbon/tar deposits on the plenum side as shown below. It is the greyish stuff on the lower portion.




To clean the TB, spray some of that TB cleaner (you can also use a very mild degreaser) on a clean towel. Push the butterfly valve to access all the necessary areas and start scrubbing it off. Once that is done, it should look good as new. Below is what mine looked like after cleaning. I also did the same for the plenum. Do not spray the cleaner into the plenum!




If your car has seen a lot of miles, it is a good time to replace the o-ring seal between the TB and the plenum.

Once the TB is clean you can now reinstall everything in reverse order. Repeat the same process for the second TB.

Edit: Made a video of the process below


Hope that helps

 

GREAT DIY!!!! Thanks for taking the time to write this up. Nominate this for a sticky.

 

You sir, are a gentleman and a scolar, and an asset to this community. Th k
you. STICKIED!

 

What mileage were you at when you did this?

 

How many miles was this performed at?

 

^doh.....

 

Good stuff man thank you for this

 

You're welcome guys

I did it today at 26K miles. Although I've been chasing my rough idle issue since 10K miles or so. I took the car for a spin today today and the idle was so smooth and response was much better. It used to fluctuate and almost stall before.

 

Thanks. I got a ways. - Mr. Off Topic

 

Great DIY, I have a rough idle and I hope this gets rid of it!

 

Kuwait FTW!! Thanks for writing this up man it sure will come in handy, I noticed a rough idle a while back but now it seems fine, or maybe I just got used to it I'm not sure.

Thanks again

 

How do you figure removing the hoses and wire harness will throw off the idle position?

 

you can remove the harness and hoses...pinch off the hoses so the coolant doesn't leak out...and disconnect the battery before u remove the harness...

 

I thought you still have to do the idle valve relearn position even if you disconnect the battery? I don't know

 

Do you recommend just a traditional microfiber cloth to clean the throttle bodies with? I'm not trying to get pieces of towel in my plenum.