Focus ST 250 engine revving issue

[Akseone]

Hi all

 

First time post, as usual with most First time posting its because I have issue with a ST250 from 2013. 

Now I have had a inkling something is wrong with the car for about a year. when I first had my suspicions it was idling over 1k revs. but no check engine light and 3 mechanics said it was ok and not to worry. Fast forward to a random check engine light a few months ago. Comes up with MAF/MAP System to Lean issues according to the breakdown service. Take it to a mechanic and the light is gone and he says it is fine probably a dirty sensor.

Recently when idling it revs to 1500-2000 rpm randomly drops to 500 and then back up again, CHEWS through fuel and sometimes stalls. The check engine light comes on and then after a week goes off again. It is driving me insane. 

One mechanic I trust but he is a ***** to get to do anything, The other told me just to remap the problem out and it could be a motor to control an intake valve and the third (a well known ford tuner in the uk) said to buy a error reader and sort myself basically.

Not really inclined to listen to the dude who told me to map it out. I also don't want to buy a error reader just to fix something myself.

Can anyone please shed some light on what it could possibly be?

[Luke4efc]

Have you got an aftermarket intake/air filter fitted?

However, if you're not willing to spend £15 on an obd2 scanner then you may aswell just take it to an ST specialist and let them deal with it. A code reader is pretty essential to fix modern cars, especially a decent one like Forscan.

[Akseone]

57 minutes ago, Luke4efc said:

Have you got an aftermarket intake/air filter fitted?

However, if you're not willing to spend £15 on an obd2 scanner then you may aswell just take it to an ST specialist and let them deal with it. A code reader is pretty essential to fix modern cars, especially a decent one like Forscan.

No aftermarket parts at all, Here’s me thinking the scanners where hundreds of pounds. I shall go and get one for sure !

[Luke4efc]

6 hours ago, Akseone said:

No aftermarket parts at all, Here’s me thinking the scanners where hundreds of pounds. I shall go and get one for sure !

We recommend a modified Elm327 and Forscan on a laptop.