Hi there, I'm Mark, and I have a problem with my Focus C-Max 1.6 TDCi.

I was looking for help on my native Polish Forums, but no help came.

I bought this car around 4 months ago, and I did not have a slight problem with it, until the revs started to go up and down slightly in idle, and when driving in 4th and 5th gear and trying to maintain the same speed in the range from 1500-1750 revs, the engine starts to jerk the car, sometimes even hard.

What I did was replacing the MAF sensor, as the old one was covered in oil due to oil vapors entering the intake from the crankcase ventilation hose when the engine is off (I know it is normal for these engines).
That replacement made the engine run even worse, and the stuttering and jerking went absolutely bonkers in this range of revs, yet it has back the power and torque it had before the problems started.

I want to inspect the MAP sensor also, but no time for that now (you know, work, etc.), yet I have to go for a long ride this wednesday, so any help would be appreciated.

My questions are:

What else can I check to make my engine run flawlessly?

Can I clean the MAP sensor? With what? How?

Sorry for my English, not my native language, and I lost the habit of constructing sentences lol also lack of vocab

2 hours ago, EmdoPL said:

Hi there, I'm Mark, and I have a problem with my Focus C-Max 1.6 TDCi.

I was looking for help on my native Polish Forums, but no help came.

I bought this car around 4 months ago, and I did not have a slight problem with it, until the revs started to go up and down slightly in idle, and when driving in 4th and 5th gear and trying to maintain the same speed in the range from 1500-1750 revs, the engine starts to jerk the car, sometimes even hard.

What I did was replacing the MAF sensor, as the old one was covered in oil due to oil vapors entering the intake from the crankcase ventilation hose when the engine is off (I know it is normal for these engines).
That replacement made the engine run even worse, and the stuttering and jerking went absolutely bonkers in this range of revs, yet it has back the power and torque it had before the problems started.

I want to inspect the MAP sensor also, but no time for that now (you know, work, etc.), yet I have to go for a long ride this wednesday, so any help would be appreciated.

My questions are:

What else can I check to make my engine run flawlessly?

Can I clean the MAP sensor? With what? How?

Sorry for my English, not my native language, and I lost the habit of constructing sentences lol also lack of vocab

Hi. I have the same problem with mine and still unable to find the cause. Have a look at my past posts and you will see. I'm still working on it!! 

Tony.

Oops I put a response in quote. Think it should have been here.....

Saved the error codes the other day, here's what i've got:

U0073-21

P193B-24

P1936-24

U0416-28

U1900-20