MAF Sensor and Throttle Body Cleaning DIY: GS400 & GS430
#31
iModerate
Personally I see no reason not to clean the temp sensor as well as the screens. Mine was filthy black on the incoming side and completely clean and shiny on the other so I cleaned it with the MAF spray. Now its clean on both sides and is working fine.
#32
I've gotten the check engine light for the second time in about a year on my 99 gs400. My mechanic says its the MAF, and to try cleaning it. But since its the second time, they say it might need to be replaced. Seems like a no brainer of a replacement. But, is it plug and go, or are there some calibration steps that have to be taken after the MAF is replaced? Anyone know roughly what a MAF costs? Thanks.
#33
Moderator - Electronics Forum
Just tried cleaning the TB and got the PO505 error. Idle, upon startup, is around 2200 rpm...a bit high. In "drive" it idles around 900 rpm.
Maybe I got some junk into an area by mistake? The carbon had a molasses like consistency. Very gunky.
Ideas?
Maybe I got some junk into an area by mistake? The carbon had a molasses like consistency. Very gunky.
Ideas?
#34
Moderator - Electronics Forum
Found out what caused the high idle. Quite a while ago I had a new TPS (throttle position sensor) installed and they never adjusted it correctly. The voltage was about TWICE what it was supposed to be. Fortunately the tech that did the job doesn't work there anymore - lots of complaints against him.
TPS sensor was readjusted and all is well now. Idles at around 600 to 700 rpm.
The cleaning made a huge difference in acceleration. TB was fairly gummed up and MAF sensor wasn't clean at all. 207k miles.
TPS sensor was readjusted and all is well now. Idles at around 600 to 700 rpm.
The cleaning made a huge difference in acceleration. TB was fairly gummed up and MAF sensor wasn't clean at all. 207k miles.
#36
On a sid note. I am in the precess of changing my starter. I left the coolant lines attached to the throttle body and left it still in the engine bay while the intake manifold is out. With the intake manifold out of the way, there is plenty of room to clean the rear of the throttle plate and bore.
Some before and after pictures:
Don't forget a new gasket:
I'm sure if I were to completely remove the throttle body assembly, I could have make it spotless. But I'm satisfied with it. Mush better now. And I did clean the MAF along with replace the stupid K&N filter with an OEM one.
#38
Maf
No, I am not getting a check engine light. The mechanic cleaned the maf, but then said it's still no good. That a new MAF is needed to work properly. I'm not sure if I should buy a new one now.
Also, If I install a new MAF, what else needs to be done relating to the ECU? does it need to be programmed at the shop?
Also, If I install a new MAF, what else needs to be done relating to the ECU? does it need to be programmed at the shop?
Also curious as to the answer to your second question on the ECU
#39
Lead Lap
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I know that on the GS400 (what I own) there are two 10mm bolts. Take a 6 sided socket and ratchet. I prefer a 3/8 drive for this situation. remove the bolts and pull the MAF out. Disconnect the wiring clip first.
On a sid note. I am in the precess of changing my starter. I left the coolant lines attached to the throttle body and left it still in the engine bay while the intake manifold is out. With the intake manifold out of the way, there is plenty of room to clean the rear of the throttle plate and bore.
Some before and after pictures:
Don't forget a new gasket:
I'm sure if I were to completely remove the throttle body assembly, I could have make it spotless. But I'm satisfied with it. Mush better now. And I did clean the MAF along with replace the stupid K&N filter with an OEM one.
On a sid note. I am in the precess of changing my starter. I left the coolant lines attached to the throttle body and left it still in the engine bay while the intake manifold is out. With the intake manifold out of the way, there is plenty of room to clean the rear of the throttle plate and bore.
Some before and after pictures:
Don't forget a new gasket:
I'm sure if I were to completely remove the throttle body assembly, I could have make it spotless. But I'm satisfied with it. Mush better now. And I did clean the MAF along with replace the stupid K&N filter with an OEM one.
why is the K&N??? is it all because of oil stickint inside MAF sensor or???i used K&N,first when i installed it the car was fast and could feel more torch but now after 2 months feels like the car lost power and.
#40
Lexus Champion
iTrader: (10)
Why would you need to adjust anything ecu when you replace the old oem MAF with a new oem MAF?
Just unplug the battery and replace it.
If you want to reset the ECU, you can search for the procedure... there was some elaborate ways to reset. I would just unplug the battery for a longer period. If it's eprom,then I would follow the procedure (it's somewhere in the forum). Anyhow, it doesn't make sense to adjust anything ecu... it's just a sensor that feeds information to the ecu.
Just unplug the battery and replace it.
If you want to reset the ECU, you can search for the procedure... there was some elaborate ways to reset. I would just unplug the battery for a longer period. If it's eprom,then I would follow the procedure (it's somewhere in the forum). Anyhow, it doesn't make sense to adjust anything ecu... it's just a sensor that feeds information to the ecu.
#41
Found out what caused the high idle. Quite a while ago I had a new TPS (throttle position sensor) installed and they never adjusted it correctly. The voltage was about TWICE what it was supposed to be. Fortunately the tech that did the job doesn't work there anymore - lots of complaints against him.
TPS sensor was readjusted and all is well now. Idles at around 600 to 700 rpm.
The cleaning made a huge difference in acceleration. TB was fairly gummed up and MAF sensor wasn't clean at all. 207k miles.
TPS sensor was readjusted and all is well now. Idles at around 600 to 700 rpm.
The cleaning made a huge difference in acceleration. TB was fairly gummed up and MAF sensor wasn't clean at all. 207k miles.
Last edited by Lust4Lexus; 03-27-10 at 10:01 PM.
#42
Lexus Test Driver
I dont understand though- what would that mechanics mistake take all this time to show its head? The clean TB all of the sudden shed light on the mis adjusted sensor? I thought that the TB on these V8's were not not opened and closed by a traditional cable, how are you guys opening up the tb? your just pushing it open with your fingers or screwdriver? I have done these 2 cleanings on my maxima numerous times over the years, but i thought the lexus TB was a little more "touchy" than the maxima, as it is electronically controlled
2001 + GS430 electronic.
400 vs 430.
I think.
Last edited by alexulan; 04-21-10 at 04:22 PM.
#44
OKay- sobeing that my LS 430 is electronic- how is the safe way to clean it? do you poke your finger against the butterfly plate? I dont want to break anything- on old steel cable on would not worry me in the least- but this car is a different beast
#45
I just did this MAF and Throttle Body DIY this morning thanks to
the OGP and the other CL'rs that posted in this thread.
Could not have done it without ya's.
I havent driven yet but the idle seemed a lot better. Cant wait to drive!!!
Check out how bad the gunk build up was in these before and after pics.
the OGP and the other CL'rs that posted in this thread.
Could not have done it without ya's.
I havent driven yet but the idle seemed a lot better. Cant wait to drive!!!
Check out how bad the gunk build up was in these before and after pics.