mpi air flow meter
Hello folks - long time since my last post!
My '99 iO (Dubai car, now residing in Mallorca) is still doing ok but failed the emissions inspection this year by some margin. As far as I am aware, the only item that controls the mixture is the MAF, as this car came factory without a catalyst and has no O2 sensor in the exhaust either. A few years ago I had the injectors cleaned and bought one new one. Additionally, the air filter is a genuine Mitsubishi part and is new.
I have no idea if there is a way to check for stored codes to see if the MAF has failed, so I thought I would investigate if I could buy a new MAF here in the UK and take it with me to Mallorca when I next travel there. My local Mitsubishi dealer can order it in but it will cost me around £700!!!! After some brief googling it looks like you can buy replica Chinese ones for pittance. I know it is nearly always a gamble going down the route of cheap Chinese knock offs and I am generally a believer in "you pay for what you get" but when the difference in price is that much, it certainly draws my attention!
I think the part number I need is MD 343605. If anyone understands how the emission control works and is able to enlighten me more than what I think I know, please do tell. Alternatively, if anyone has had to replace this MAF in the past, what part did you buy?
Cheers, Guy
The other routes to consider
The other routes to consider are a good used unit or a company that will rebuild and test yours. Thing like abs units, ecu, and off dashes have expert companies that will take it apart and warranty it. It could be posted anywhere in the world, just get a good courier.
Also the fuel varies around the world. If possible used 99ron with e5 or e0 .
Don't mention Mitsubishi prices, we all know we need to be sitting down to hear them!!!
Repair! I didn't know MAF
Repair! I didn't know MAF meters could be repaired. I will certainly look into this.
Yep, also thought about a used one but they appear to be rare and/or on the other side of the globe from me. Not rulling it out as an option but a bit of a risk!
Thanks
I only use basic tools but an
- I only use basic tools but an electronics engineer with the right manual can at least do basic checks ,maybe cleaning and component replacement (could be tv or computer repairer not car). Usually oe quality parts properly repaired last longer than Chinese junk.
- I'd get more diagnosing done to get the most evidence to point to a solution. Fault codes, visual checks of wiring etc.
- Emissions can be affected by burning oil or water. Ie wear.
- I'd have thought most modern fuel injection cars need a lambda probe for the ecu to know the correct air fuel ratio. As this is cheap and if you must do part swap diagnosing,that is what people start with. Or as you said this method gets expensive and frustration filled.
- Weirdly buying a complete car can be cheaper than a couple of parts. Breakers yards get rich doing that. Strip and sell on/crush remains.
- Can't recommend any uk breakers must Google.
Problem resolved
It has been a while and I have some time so remembered I ought to conclude this thread.
The reason for the poor emissions was a vacuum leak. It turned out the throttle body gasket (throttle body had never been removed) had a tiny crack where it must have shrunk and got brittle over the years and this was allowing air in. The crack was tiny and it is amazing how much it affected the mixture.
New gasket in there and emissions back to normal. Spanish ITV passed and all well again 
Best wishes, Guy
Syndicate
You need to know which numbers were high...
So you failed an emissions test by some margin - that doesn't give us much to work with.
What are they testing for? Hydrocarbons? Oxides of nitrogen?