misfiring and tried everything! help

[ross2786]

car is misfiring and im not happy
i have changed the plugs, leads, had the timing redone put standard filter back. i had a KandN filter fitted before.

i also have a ktr s/s exhuast with decat pipe, would back pressure be a cause of this

 

[Pedro]

Checked the upstrem o2 sensor on the manifold?

 

[ross2786]

no, i had my mates computer on and that and the catalyst came up as unchecked

 

[ditz]

not checked the coil pack?? you are best of actually diagnosing it rather than throwing parts at it...

what dosn't it have???
pull each lead off the coil pack check each is sparking

 

[172Ben]

Injectors? Mine had a dodgy number 3, unplugged the connectors, all ran lumpy when unplugged apart from number 3 which made no difference when unplugged.

Worth a shot

 

[davM]

coil pack/injector?

 

[mark smith87]

coil pack is weak point on these cars. If they get wet they can fail.

 

[ross2786]

had it diagnosed with a new and old coil packs. it was saying that 2 and 4were missing and tried it for the last time and 3 was missing