Hi all,

My focus 02 has been juddering for a few weeks while accelerating, mainly in the mornings. on the way to work this morning it was juddering badly and the engine management light was flashing. i took it to a garage and they put the diagnostics on it but nothing came up, they checked under the car and my front exhaust needed replacing, the mechanics said that it might fix the problem, im concerned that the misfiring will continue, any ideas?

p.s had the spark plugs changed about 8 months ago and the coil pack replaced about 3 and a half years ago

cheers, Daz

hard to tell what the problem could be it might be a intermitant fault in sensor in the manifold or the air intake (mass sensor ) regulating air intake worth checking

thanks, it only seems to do it at the start of a journey, after a bit of a run the engine evens out again, the mechanics said that becuse of the broken front pipe the engine wasnt getting ebough power that could cause it to misfire, the engine light is off now. its a bit scary at junctions and roundabouts when you need to pull of quick but the thing wont go!

i woud have thought if the pipe was broken the problem would always be there cold or warm. more likely to be electrcal or sensor i would think

on another note some garage's have a data logger that plug's into your car and as you drive it records the engine input/output that can help them find the fault?

thanks mark, i'll take it for a run later and see how it goes, they said to bring it back if it carries on.

It may have been over or under fuelling because of bypassing due to the damaged exhaust.

Could be a plug lead problem No1 and No2 seem to suffer with this for some reason test the lead if one is wildly out then thats your problem. Remember the shorter the lead the less resistance with out going and checking I think they should be about 4-5ohms per foot. hope this helps.