what could it be now

[userunknown]

ford escourt zx2 2.0 dohc has rough idle got the car in feb 08 ran just fine previous owner had o2 sensors replaced i change fule filter spark plugs wires oil oil filter and still has rough idle not noticeable when driving except in low rpms on take off and at 35mph in forth gear i have had a car just like this and it never had any problems untill i romped on it for two years or so and then it needed a tranny and a clutch but thats be side the point i took it to deq for regular test and they said it wasnt test ready it needed to go through a drive cycle so i drove about 3 to 4 hours and took it back hot and still wouldnt read they told me to call the dealership to find out what the driva cycle is for the sensors that arnt reading (cat,heated o2,evap,o2) the dealership wants 260 to run tests but i got three weeks till my trip permit expires fill me in ill be waiting

[userunknown]

i forgot i also replaced the timeing belt and saw that a couple threads up someone has simalar propblems so how would you adjust the timeing belt if all you do is take one off and put new belt on spine it around or what

[mightymoose_22]

A bad idle can also be a result of a small vacuum leak. Inspect all vacuum hoses and the intake manifold to find out if extra air is being sucked in.

[Davescort97]

Ditto on the vacuum leak. It will make the engine idle rough.