Hi guys,

FOr the last 15 months or so I have had an `engine systems fault` message permanently on (no check engine light though) also a slightly noticable loss of power (acceleration feels limited no matter how hard I press the pedal- top speed isn't limited it just takes much longer to get there)

I have had diagnostics done (cost me £100) the guy said it is definitely not an injector fault, other than that he doesn't know what is wrong.

Ford want £120 just to diagnose the problem, money which we frankly do not have.

Doing some online research the EGR valve and MAF sensor consistently come up as possible culprits. I have taken the vac hoses off the EGR and sprayed cleaner into it with it still on the engine. I have removed the MAF and cleaned that also- neither of these has fixed the problem...

So, given that my car has done almost 100k miles, it has FSH but neither of those parts has been replaced that I can see, would it be likely that the EGR and/ or MAF need to be replaced rather than cleaned?

Thanks for any input :)

I would start by blanking the egr valve off, costs a fiver and can fix the egr problem. As for the maf, disconnect the maf sensor wiring does the car run better?

Disconnect the MAF sensor and then turn the engine on? Won't that do damage to the engine?

I will try the EGR blanking tip, need to read up on how to do it but thanks for the advice!

Nah no damage. The sensor just helps to get the fuel air ratio perfect. But if it's reading incorrectly it will already be throwing too much or probably too little air into the system. Disconnect it and you will run on ad assumption value and you likely will find it improves it.

So I disconnect the plug from the MAF sensor, turn on the ignition and then.... what am I looking for? Do I drive the car? If the light goes off it means it's the MAF at fault? Or am I looking for the light to stay on? Sorry if this is obvious but I'm a little confused...

Just drive the car as you normally would, your looking to see if f it drives any better generally speaking than it did before disconnecting it

Ok disconnected the MAF sensor, took the car for a drive (about 6 miles, combination of regular roads and dual carriageways, couple of things to note:

1) With the MAF disconnected there was a definite improvement in overall feel of the car- acceleration seemed much better and not as much hesitancy through the rev range as there was previously

2) the engine systems fault message/ light stayed on and I also got a check engine light as well- are these both expected given that I've unplugged the MAF?

So the improvement to the car with MAF unplugged is this indicative of a need for a new MAF sensor?

If I buy one is it simply a case of replacing the old for the new and it'll be fine? Or do I need to reprogram/ reset the ECU or something like that?

Thanks for all your help :)

Glad it helped you. The fact it improved suggests it's playing a part in it.

First job is to get some electrical contact cleaner

Then remove the sensor and spray liberally. Leave it to dry, then repeat every half hour for a few hours. That allows the maximum cleaning of the sensor and if it still doesn't work then you canl at removing it and replacing it.

OK, took the sensor out, cleaned it as advised, put it back in- exactly the same problem however the CEL is (worryingly) permanantly on now wether the MAF sensor is plugged in or not. I have a cheap blutooth OBD reader and my phone app tells me 2 codes (can't remember what they were exactly but both had MAF on them! If it's any help for you lovely people I could reconnect it and take a screenshot of the codes but even to my limited tech knowledge the fact that both codes say MAF is fairly self explanatory :) )

So is my next step to buy a new MAF sensor? When/ if I buy it do I just plug it in and start the engine? Or do I need to unplug the battery/ reset the ECU or something else as well?

I think it may be a sensible idea but before you do, take a snap of the codes. There's more to the maf than the sensor.

Ok these are the 2 codes the OBD reader is picking up:

Actually, the above codes have only shown up since disconnecting the MAF sensor, I have just used the code readr to clear the CEL, plugged the MAF back in and there are now no codes but the "engine system fault" message still comes up. So, presumably the CEL was just telling me that the MAF wasn't connected but since reconnecting it hasn't actually fixed anything do I need to change the MAF sensor?

Oh forgot to put a pic of my MAF, taken after several hours of 30 minute interval blasts with electrical contact cleaner, not sure what I'm looking for here, seems to be clean so maybe it's broken?

That sounds like something else then, you need to get a proper code read done, such as the likes of forscan with a USB otherwise a professional diagnostic. If the maf was solely to blame there should be an error