Save Your Some Money - Better Mpg

[davepruce]

I had a look at this (armed with my IPA to clean it)- it appears to be connected to something , but when you actually pull it out from inside the air box, there is just a plastic looking pointy thing (s**t description - but thats what it looks like).

Is this plastic thing a sensor ?

Yup Air Temp Sensor

I'm confused too Ian .... I took what I assume to be the MAF sensor (top of the air intake, engine side of the filter, 3 small bolts holding it in, about 4 inches by 3) out last night and could see no wires or anything that could be cleaned!

It has 2 errr 'posts' that stick into the airflow, but what either of them do is a mystery. I didnt want to poke them around too much just in case, so anyone that knows how they work on an LS400 Mk2, please enlighten me (and anyone else).

Cheers

Dave

One of the "posts" is the Air Temp Sensor and the other is like a tube. Look up the inside of the tube and you will see 2 thin wires, those are the ones you want to clean :D

IS300 and Altezza have a MAF and IS200 has a MAP with separate temp sensor in the air box.

Thanks MacRS200, I'll have a look this week and report back

[DINO]

IS300 and Altezza have a MAF and IS200 has a MAP with separate temp sensor in the air box.

So where is the MAP sensor on the IS200.

[Noel]

I do clean my Tezza's Maf sensor and it was dirty first time, but didn't notice any difference.......

Cleaned it again there recently when i put on the Induction kit... just in case and more so because i now have this great big can of contact cleaner... lol

Sorry for going slightly off topic....... but from what i gather ....

Having a clean MAF sensor improves economy and performance? but if having a dirty sensor reduces economy does that not mean the ECU is sending more fuel to engine.... Would that not also increase performance down low and reduce it and high levels......

Anyone able to follow my logic....... does it make sense?

[ColinBarber]

the engine should supply the correct amount of fuel throughout the rev range. If you are getting the correct amount of fuel then supplying more will decrease performance.

If you have an induction kit you may find the fueling isn't 100% correct throughout the rev range, it may be lean at certain points and rich at others. You would need to put the vehicle on a rolling road to find out.

[IanB]

Did mine at the weekend, 5 minute job.

What a difference to general driving, feels smoother and a lot more responsive, not sure about MPG yet, will have to wait and see.

Did mine today on my IS300. As you say, simple. My MAF sensor looks exactly the same as one on the RX300 link on Felix's orginal post.

I too will see what happens to fuel consumption, but performace doesn't seem any different.

IanB :D

[DINO]

I had a look at this (armed with my IPA to clean it)- it appears to be connected to something , but when you actually pull it out from inside the air box, there is just a plastic looking pointy thing (s**t description - but thats what it looks like).

Is this plastic thing a sensor ?

Yup Air Temp Sensor

I'm confused too Ian .... I took what I assume to be the MAF sensor (top of the air intake, engine side of the filter, 3 small bolts holding it in, about 4 inches by 3) out last night and could see no wires or anything that could be cleaned!

It has 2 errr 'posts' that stick into the airflow, but what either of them do is a mystery. I didnt want to poke them around too much just in case, so anyone that knows how they work on an LS400 Mk2, please enlighten me (and anyone else).

Cheers

Dave

One of the "posts" is the Air Temp Sensor and the other is like a tube. Look up the inside of the tube and you will see 2 thin wires, those are the ones you want to clean :D

IS300 and Altezza have a MAF and IS200 has a MAP with separate temp sensor in the air box.

Did mine at the weekend, 5 minute job.

What a difference to general driving, feels smoother and a lot more responsive, not sure about MPG yet, will have to wait and see.

Did mine today on my IS300. As you say, simple. My MAF sensor looks exactly the same as one on the RX300 link on Felix's orginal post.

I too will see what happens to fuel consumption, but performace doesn't seem any different.

IanB :D

So where is the MAP sensor located on the IS200. And how do I clean it.

[ColinBarber]

you don't need to clean the MAP sensor.

[leedsunited]

you don't need to clean the MAP sensor.

On what basis are you making this statement?

[IanB]

This debate has got me curious about the difference between MAF and MAP sensors. Here's an interesting one on MAF (Mass Air Flow) sensors. It may be about Fords, but there's some interesting stuff for anyone having auto gearbox problems. I don't know if this applies to Lexus gearbox's though :duh:

http://www.fordscorpio.co.uk/cleanmaf.htm

http://en.wikipedia.org/wiki/MAF_sensor

And here is something explaining what a MAP (Manifold Absolute Pressure) sensor is:-

http://en.wikipedia.org/wiki/MAP_sensor

It does explain why the MAP sensor doesn't require cleaning though i.e. it doesn't have a hot wire to get contaminated. It's basically a pressure gauge.

Happy reading!

IanB :D

[ColinBarber]

you don't need to clean the MAP sensor.

On what basis are you making this statement?

because it's a pressure guage which isn't really affected by dirt and is also not in the direct air flow and therefore not subject to as much dirt.

The hot wire MAF sensor needs cleaning because one wire heats and the other one reads the air temperture. If dirt gets on the wires they become more insulated and therefore it goes out of calibration. Things are even worse because the hot wire, in becoming hot, tends to attract dirt which gets baked on.

[DINO]

Nope IS200 has a MAP sensor and you don't need to clean it.

So the IS200 is superior? :D

, no.

The MAF sensor gives slightly inaccurate air readings when dirty, the MAP sensor does it all the time :winky:

Hi can anyone tell me where the MAP sensor is onthe is200 and how do I clean it. TKS

:D Hi can anyone tell me where the MAP sesor is on the IS200 and how do I clean it, although it has been stated it does not need to be cleaned.

[Noel]

Well if Colin says you don't have to clean it, then you don't have to clean it...

I'm probably wrong but if it stands for "Manifold absolute pressure" then it might be around the manifold somewhere.... :P

[postie]

I had a go at this on my RX300 and it works a treat! definetly improved fuel consumption!

[cnrke1]

Hello everyone,

I was wondering if any of your have been reading this in the knowledge base:

http://www.lexusownersclub.co.uk/knowledge...id=152&c=11

I have done it; I used "contact cleaner". It costs £2.49 from Maplins.

The MPG improved from 15.5 to 18.5 (mixed driving)

Very easy to do, you can get your money back with in your very first supermarket trip.

Felix

:D

Thanks Felix will try that out tomoz. She needs a good detail and service anyway.

Job done and while I was at it I cleaned the air intake valves on the manifold with injection/carb cleaner. The car started in a cloud of smoke.

[Cymro]

Having read with interest this thread about cleaning the MAF sensor on the RX300, Mk 1, I've just been told that I need a new oxy sensor. [That follows a dealer check after 2 warning lights (engine management and VSC) appeared]. The sensor costs £150+, plus fitting.

So I wondered whether, like the MAF sensor, the oxy sensor can be cleaned?

If so, where is it and how do I get at it to clean it?

[IanB]

Did mine today on my IS300. As you say, simple. My MAF sensor looks exactly the same as one on the RX300 link on Felix's orginal post.

I too will see what happens to fuel consumption, but performace doesn't seem any different.

IanB :D

Just an update. I've only been doing local mileage since cleaning the MAF sensor, and it's been averaging around 23 mpg. Lots of short journeys though (less than a mile) and some trips of 20 to 30 miles. So perhaps it's not so bad, but no real improvement on what it did before cleaning.

I'll see what it does next time I do a decent motorway run.

IanB :D