.. I'm getting about 2 more mpg

Evidently it's safe to clean the 1998-2000 LS400 with CRC MAF Sensor Cleaner since it isn't the Karman Vortex type of the earlier LS400's. Sure enough it has TINY little hot wires in it -- which you can see if you hold it up in the light just right.

I did just over 15 sprays of the CRC MAF Sensor Cleaner holding it almost upside down so the fluid drains back out. I also squirted it in from the sides a bit to clean the "gills"

I don't know how close you guys spray your 98-2000 maf sensor, but I had the tip of the red spray straw about right at the end / entrance of the maf sensor. I had it backed off even further than that but figured I could get it a little cleaner by getting a little closer. Though, I was worried about the force of the spray damaging the wires but it turned out ok--THIS TIME.

 

Good to hear! So how many mpg do you get on the streets?

 

I was getting like 15 1/4 mpg now getting 17.2 mpg in the streets.

 

Will doing this also improve the mpg on a 1995 Celsior/LS400?

 

I don't know what 90-97 LS400's owner's can do for thier car since it is a Karman Vortex MAF. They are very sensitive and have read numerous threads about their MAF not performing properly after using CRC MAF Cleaner on it.

 

It was only pre October 1994 LS400s that had the KV MAFS so models after this should benefit from the cleaning.

 

If you have a Karman Vortex MAF don't touch it. You don't want to spray anything on that.

 

i would think your 98 would get better mpg than 17.5 since you have an extra gear. i get 18mpg city in my 97, with a dirty MAF.

 

Timmy, I still have to clean my throttle body. And *possibly* replace ECT sensor and ECU capacitors. I do have about 80lbs in the trunk too, that I need to put in storage.

The plugs are 60k miles old (6 years old) but the dealership said they're good for 120k.

Anyways, regardless, I'm happy I am getting 2 more mpg after cleaning my MAF sensor

 

So the the improvement is 12.8%. Congratulations on your success.
In my case on my 98 Celsior, it was a little less than 10% and your result is a bit better.

 

The vvti's love high octane too. Best mileage I have seen is when I run 93 and a bottle of Lucas product, which is similar to an octane boost but with other additives. If you have not tried it try it out. I can really feel a difference with the Lucas product. I like their stuff.

Has anyone ever looked at how the stock computer handles over 93 octane? I wonder if it can advance the timing more with high octane fuel. Put a little jet fuel in there and see what happens.

 

octane 93?? The lowest we have is 95. Best we have is 98. germany even has 102 !

 

So i could clean it with the special MAF cleaning stuff? Sure about the year? I have a 95 model.

 

the way most european countries calculate octane is different from the US. The US, Canada, and a couple other countries use R+M/2 instead of just the RON number.

for example, 98 Super in europe is ~93-94 octane in the US. Ultra 94 in canada is ~102octane RON in europe.

Aral Ultimate 102 in Germany (RON) with a supposed MON of 88 yields a US rating of 95 octane.