Higher MPG after cleaning MAF & throttle body

[JavierHG]

Hello everyone

This is my first post therefore please bear with me. I have a 2009 IS250 SR with 111.500 miles.

Before i cleaned the MAF and throttle body i was getting around 24-25 mpg driving in London roads as per the computer, now the computer says it's 19-20 mpg

Once thing that i didn't do is disconnect the Battery, does anyone know what the reason for this change?

[Texas]

Do not a higher mpg but lower then?

[Mr Vlad]

You've probably confused the throttle butterfly sensor by not disconnecting the Battery.

Look up throttle body re-learn which should cure your problem. I did mine months ago and my mpg got better by about 2mpg.

[Mr Vlad]

Actually no need to disconnect the Battery, what I did was to disconnect the multiplug on the throttle body. Just remembered. 

[JavierHG]

1 hour ago, Mr Vlad said:

Actually no need to disconnect the battery, what I did was to disconnect the multiplug on the throttle body. Just remembered. 

Should i do that and leave it disconnected for a while or just disconnect the Battery terminals for an hour?

If i disconnect the Battery, do you know if there will be any issues, like loosing the channels in the radio or the radio asking for a code?

Thanks.

 

 

[Mr Vlad]

Hi Javier. Yes I suppose you can try to just disconnect the multi plug and leave it a while and plug it back in. You could also just have a look at the butterfly and check for debris (whilst the multiplug is disconnected). 

Out of interest when you did the clean, was the engine idling higher than normal like 2.5k revs for instance?

[chr15gb]

1 hour ago, JavierHG said:

 

If i disconnect the battery, do you know if there will be any issues, like loosing the channels in the radio or the radio asking for a code?

Thanks.

 

 

No, none of that nonsense. The only thing will be the windows to re-learn.

[JavierHG]

1 hour ago, Mr Vlad said:

Hi Javier. Yes I suppose you can try to just disconnect the multi plug and leave it a while and plug it back in. You could also just have a look at the butterfly and check for debris (whilst the multiplug is disconnected). 

Out of interest when you did the clean, was the engine idling higher than normal like 2.5k revs for instance?

Ok i will try to find and disconnect this multi plug you mentioned, if i cannot find it i guess i will have to disconnect the Battery terminals

Yes it was idling higher than normal and i've followed your post from January 15 in regards to reducing the idling

Thanks for your help

[Texas]

5 hours ago, Texas said:

Do not a higher mpg but lower then?

Dohhh! For ‘Do’ read ‘So’!

using an Iphone (without your reading glasses) whilst in the works van ( as a passenger I stress) is obviously not the best.

[BC99]

somehow damaged the MAF during cleaning? MAF sensors are 🤬 and don't always take kindly to being cleaned.

Could just be relearning though after resetting.

[JavierHG]

8 minutes ago, BC99 said:

somehow damaged the MAF during cleaning? MAF sensors are 🤬 and don't always take kindly to being cleaned.

Could just be relearning though after resetting.

Not sure if this is the case as i was very gentle and i've done 50 miles after cleaning so i would assume the resetting has been done, but i will check how many miles i get per full tank and compare it to the 280-300 i was getting before

[is200 Newbie]

E10 fuel ... supposed to be less efficient - has anyone seen any evidence of this reported through cars ECU?

 

[JavierHG]

23 minutes ago, is200 Newbie said:

E10 fuel ... supposed to be less efficient - has anyone seen any evidence of this reported through cars ECU?

 

This is what i was thinking but wasn't sure if before cleaning i was filling it with E10 or not but could be, even though i just read this in the gov webpage:

Fuel economy

Using E10 petrol can slightly reduce fuel economy (the number of miles you are able to drive on a gallon of fuel). You may see a reduction of around 1%, but it is unlikely to be noticeable in everyday driving.