MAF Sensor Cleaning... Do It!

Anonymous · April 9, 2004, 13:31

Cleaned the MAF sensor earlier, now before I go on, please bear in mind that I was fairly sceptical as to whether or not it would provide any benefit.

Anyway, I removed the sensor, squirted it with some Halfords electrical contact cleaner. I must admit that I thought that the wires inside looked fairly clean before I had cleaned them. They were a kind of brassy colour but looked like that was how they should be. After cleaningt however the wires were a shiny silver so even though it didn't look like they needed cleaning, they definitely did. I also sprayed the contacts on the plug on the MAF sensor whilst I was at it.

After waiting for the cleaner to evaporate and reassemnbling I went for a quick drive, expecting there to be no noticable difference - I was wrong. Although not a massive difference, it's definitely noticable. The engine idle seems more stable and the engine revs more sweetly, feeling more responsive. Put it this way - my 5min test drive turned into a 30 minute qualifying session - I just couldn't help myself.

Our 2 is only a year old and has only covered about 8K miles in that time - has just been serviced. For the short time it takes to carry out I reckon it's worth cleaning every 6 months. All you need is a phillips screw driver a can of contact cleaner (£3.49 from Halfords) and about 2 minutes of time.

I didn't reset the ECU so I know that the result is purely down to cleaning the MAF. I have just removed all of the fuses for the ECU and am about to go back out and replace them to see if ressetting the ECU provides any noticable difference.

Back in a mo...

Anonymous · April 9, 2004, 14:13

this might sound thick but where is the maf sensor?

?

is it the one after the intake s:oops: :oops: s:oops: s:roll: :roll: s:roll: s:oops: :oops: s:oops:

Anonymous · April 9, 2004, 15:48

The MAF sensor is the one that has Denso written on it and is mounted on the plastic pipe that feeds the airbox. It has a flat electrical connector feeding it.

Just got back from test driving after resetting the ECU - din't think there would be a major difference but the engine seesm more eager to rev and feels less harsh at the top end of the rev range. A subtle but worthwhile improvement. I don't know whether the difference is due to the ECU recalibrating itself to the now clean MAF sensor or whether it has simply optimised itself for my driving style - plenty of revs. Either way it's worth doing.

Tem · April 9, 2004, 20:56

This might help:
m http://www.spydermagazine.com/2002/Marc ... _clean.htm m

Anonymous · April 11, 2004, 00:06

Kris:

Quotesurely that's 'restoring' performance rather than improving it as it would have come out of the factory clean...?

I understand your point Kris but lets not split hairs - at the end of the day, anyone who's driving around in a 2 that's not factory fresh will notice an improvement in performance over the current level or restoration of the original performance, depending upon how you want to describe it. Either way you win!

Anonymous · April 11, 2004, 11:05

I wasnt questioning the procedure and i know it will help restore performance, but that quote was from your post in performance with a title of "Improve engine Performance for £3.49", whats waht i was questioning.

At the end of the day your not going to get anything better than factory fresh performance so its rightfull place is here in maintenance rather than performance, thats all.

Anonymous · April 11, 2004, 15:17

cleaned mine a couple of weeks ago as the little sensor had turned a nasty black colour s:shock: :shock: s:shock: anyway, took it out for a drive after and didnt notice any difference.

How do you reset the ECU by the way? as my engine idles very low when warm (bout 500 rpm) diconnect the battery for 10 mins? tried takin out the ECU and engine idle fuses but made no difference.

Anonymous · April 11, 2004, 23:28

I took all of the ECU fuses out - 2 out of the side of the dashboard and 1 out of the engine bay fuse box. Left it for about an hour and then replaced. Definitely made a difference. Disconnecting the battery should do the same.

Tem · April 12, 2004, 21:42

Quote from: "RUSTY"Disconnecting the battery should do the same.

And probably a bit more...like losing stereo settings s:? :? s:?

Anonymous · April 12, 2004, 23:59

good point tem, cheers for reminding me, was going to do that tomorrow.
ill just take fuses out again instead, by the way i could only see one ECU fuse and that was number 32 or 33 or something which was in the engine bay, couldnt see any others? does it really matter how long you leave them out before the ECU resets itself?

Anonymous · April 13, 2004, 06:58

On the pre '03, Sony stereos disconneting the battery doesn't wipe the settings on the stereo. FWIW.

Tem · April 13, 2004, 07:08

Quote from: "Tomr2"does it really matter how long you leave them out before the ECU resets itself?

Time matters, but I don't think anyone really knows the time. Then again, if you have installed aftermarket stuff that have large capacitors within them, you need to keep them off for longer to drain them...

I've always played it safe and took them off for overnight or for a workday. Doesn't harm to keep it off longer than necessary s8)

s8)

Anonymous · April 13, 2004, 08:41

Just a quick note - when I took all of the ECU fuses out, the stereo had reset when I put them back (I have an aftermarket Kenwood unit). Unless anyone knows which exact fuse to take out to drop the power from the ECU without affecting the stereo then you may as well just disconnect the battery

Anonymous · April 13, 2004, 08:45

Quote from: "Tomr2"good point tem, cheers for reminding me, was going to do that tomorrow.
ill just take fuses out again instead, by the way i could only see one ECU fuse and that was number 32 or 33 or something which was in the engine bay, couldnt see any others? does it really matter how long you leave them out before the ECU resets itself?

There's another fuse box in a panel located at the left end of the dashboard - you will have to open the door to see it - there are 2 marked for the ECU.

Anonymous · April 13, 2004, 15:01

When i disconnected my ecu last summer i was expecting problems with my alarm. Had no problems what so ever though. How come?? (it's a cat 1 autowatch)

going off topic slighly, I have a small scanner to show the car is armed which i took off my old car. It allows you to change the pattern but the moment you set the alarm, it goes back to what it was before s:roll: :roll: s:roll: !!! any ideas? Didn't used to do it on my old car.

Anonymous · April 14, 2004, 23:42

Just for the record - the engine still feels much better than before meddling. A definite improvement and not just the placebo effect.

Anonymous · November 20, 2005, 16:39

Saw this thread a while ago, and was a bit sceptical about what you were all saying. It all sounded to easy and I wouldn`t believe that it would make any difference s:roll: :roll: s:roll:
Anyway... today I found myself with a fair bit of spare time, so I popped down to Halfrauds and picked up the said cleaner and got to work on the MAF. After I took all 3 ECU fuses out and left them for a few hours until putting them all back in... job done?!?
Took the 2 for a spin and didn`t notice anything, until I put my foot down a little and it just seemed more responsive as though it was breathing more easily s:D

s:D s:D

s:D

I`m not mechanically minded person, but this is one piece of maintenance that I`ll be carrying out a couple of times a year.

Sorry to all those that I`d doubted... Won`t happen again s:wink: :wink: s:wink:

Anonymous · November 20, 2005, 17:56

did mine on thursday, amazed at the difference, well worth doing folks.