MAF Sensor and Throttle body removal how to

After removing the plastic engine cowls by undoing the phillips screws marked in red



Marked in red you can clearly see the Throttle body linked by a rubber gator to the MAFSensor



Marked in white you will see the position of the 3 stainless steel clips that need to be removed as you see i have already removed 2 of them



Remove the throttle body by gentle manipulation , use of a little fairy liquid might help if its stiff, the power cable is long enough so at to rest it to one side



Here lined in yellow above are the two spring clips that connect the Maf sensor housing to the airfilter box un do these and let them hang down , also under the rubber gator lined red is a pipe union this can be left in place as the Maf sensor housing can be gently manipulated out ready to disconnect the electrical connector below



Note the hollow star shaped screws you will have to un do to remove the Maf sensor from its housing , worth checking before you start that you have one in the right size



Once the screws are out you can gently withdraw the Maf sensor making sure to be very careful , the O ring will make it stiff at first , but be firm and careful, inside are fine filament wires that are very fragile shown below





You can now either fit your new Maf sensor or as in my case give it a good spray with Maf sensor cleaner, and then re-assemble back into its housing , worth applying a the finest smear of silicone grease to ease around the O ring to make sure it goes home easily , also worth taking 5 minutes to clean the inside butterfly of the throttle body housing , it does get caked up a little in there. Now you are ready to re-assemble everything in the reverse order.

regards loz

Nice one Loz, that MAF is looking very similar to an Alfa, any part numbers on it, I assume its Bosch?

Conaero said:

Nice one Loz, that MAF is looking very similar to an Alfa, any part numbers on it, I assume its Bosch?

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As it happen it was bosch, didnt think to look or take the part no it'll be on eurospares site

pretty sure thats an Alfa V6 MAF, Ill see if I can get Mike to confirm.

Excellent Loz,
Another easy to follow, valuable how-to,
Many Thanks,
Enzo.

Nice Loz!

Please keep us posted on whether this helps eliminate the often cited "weak" starts.

Only driven the car a few times since JP, and no weak starts as yet , but to be honest i only had the odd weak start so time will tell , it hasn't cured my throttle response issue which is what i was hoping , its still a fair bit slower than my 4200 response wise , had no dash lights maybe i'll get it stuck on a diag next time im near a dealer


regards loz

Loz, did you put your new spark plugs in the GS or 4200? Maybe this might help? I noticed improved responsiveness with my new plugs...but it could just be in my head

JP, must admit, plugs were my thought when thinking about weak starts.

I will say though that I still had occasional weak starts during my Dubai trip, despite brand new Denso Iridium spark plugs installed...MAF needs to be cleaned so I can isolate problem...let's see what Loz experiences in the coming weeks.

Excellent guide! Just followed this through without a hitch. I had to borrow the S25 tool to get at the MAF. Its also worth mentioning the stainless steel clips in picture 3 require a special tool to clamp them back on. Cleaned the MAF using carb cleaner (believe its slightly more abrasive that MAF cleaner best so use the correct stuff if you have to hand) and notice a bit of dirty oil in the throttle body butterfly so cleaned that also. Many thanks for putting this guide together!

Interested Alex whether you noticed any difference



regards loz

I didnt notice any difference but am experiencing hessitation at 2.5k revs and am trying to narrow down the cause... clearly the MAF wasnt at fault but it was worth a shot.

Thanks for the how-to Loz. Worked a treat.

Just a couple of supplimentaries...

The hollow star-head screws that hold the MAF sensor in place are 5 POINT and not 6 point (at least they were on mine). Caused a bit of consternation as Halfrauds don't have them either, but an electrical screwdriver is exactly the right size to place across two of the star points and with careful rotation the screws can be undone without damage.

Don't skimp on the MAF spray. I checked the elements a couple of times under a magnifying glass and it took a good soaking to get them sparkly. The cleaner evaporates very quickly, so don't be alarmed at the amount of liquid initially.

And some photo's for part referencing. They are before cleaning the sensor, so not exactly filthy in the first place, but having just taken the car for a quick blat, it does seem to have made a difference.

Another Loz masterclass. Thanks mate. A useful annex from Miles too. Good work guys.

Hi I was just wondering what spray product you use to clean the Maf sensor .

Anyo said:

Hi I was just wondering what spray product you use to clean the Maf sensor .

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Hi Anyo and welcome.

There are many MAF cleaners on the market just go to any reputable auto store such as Camberly Auto Factors and ask for it. I know Wynns do one and their products ate very good.

Hi Anyo, I used Liqui Moli Air flow sensor cleaner as per my post above. I got it delivered from an Ebay shop.

Beautiful thank you very much . Got a 4200 02 spyder and it runs fantastic never ran rough and always good on fuel. It alarmed me the other day when the engine light came on and has stayed on but car still runs perfect. Got my hands on a obd11 scanner and its diagnostic was the MAF sensor hoping cleaning it will work, and when I reset the computer hope the engine light dose not appear again ?

Fingers Xed for you Anyo...let us know how it turns out


P