Technical A little help please

[bigfathairybiker]

Hi,

Just bought 2nd hand Stilo 2002/ 70k miles.

Was ok on test drive! ( private purchase not dealer )

But then a couple of days after purchase decided to show up a engine fault and the idle problem.

Cleaned the butterfly valve as best I could and this resolves the idle problem to the point that it doesnt stall now and I dont have to rev it to pull away.

But, Idle still jumps a bit but not as much.

Before clearing the DTC's and emission data there was a Petrol tank sensor code, a Post CAT O2 sensor code.

After AND before clearing, the LTFT reads -90 to -100% with the short term jumping about as usual.
The Post CAT O2 READY shows as NOT READY.
Pre CAT O2 between 0.1 and 0.9
Post CAT O2 between 0.01 and 0.16

Before I go and change the Post CAT sensor the Air filter ( will do air filter anyway as cheap! ) anyone have any other suggestions on what to check/replace?

Thanks,

Mark

 

[5abr3]

Approximate rev values for the irratic timing might help anyone familiar with the Stilo's engine. If it is only a small fluctuation it migh be the ECU dealing with the winter conditions!

 

[volxstu]

Sounds like lambda gone.