ok, so I have as a daily grind a 2000 focus 1.8 lx with the black top zetec fitted and its got a bloody annoying idle thats starting to wind me up and I can not diagnose...

Today I took out the code reader and throught id get some screenshots, as its not throwing up any errors and hope someone can point me in a direction to fix the thing that will work as im running out of ideas..

It does this after it has warmed up, the idle goes really rough like it wants to stall and on occasion it will stall, if you give it a little gas, it runs fine without problem but you end up sat in traffic doing 1200rpm, all pictures were taken with no feet on the pedal, at idle..








anyone got any idea what it could be as im stumped

 

Mass Air Flow is too low. Therefor the basis of the mixture calculation is lean.
Oxygen sensor 1 is almost at 0 volts, which means a lot of oxygen still in the exhaust gas.
Short term + Long term fuel are adding about 60% fuel, but that's not enough.

Air mass sensor dirty/aged/defective or an air leak after the air mass sensor.

 

Excellent info

Thank you!

I had suspected that befote - I cleaned the air mass a couple weeks ago so it is not dirty, had a minor effect on the idle but nothing significant.

I will check this out and firstly check for air leaks and then replace the sensor and report back.

 

Absolute throttle position 15.3%

presuming this means the tps position it seems high if your not touching any pedals?

 

check any pipes on or around the manifold they are prone for splitting on these and giving your exact symptoms

 

I agree with botters, we have seen this many times on Focus, and its usually the rubber vacuum pipes under the inlet manifold. About 18 quid from Ford for new pipes and T piece.