Right then. I have a slight misfire that is worse sometimes than others... its Fine at higher rpm but only really at idle It's noticeable. Could this be a O2 sensor... checked the voltage and one is like .20 volts lower almost constantly. Could this be the culprit?

Generally, O2 sensors won't cause the misfire. I'd suggest looking elsewhere. When is it misfiring and from what cylinder?

Generally, O2 sensors won't cause the misfire. I'd suggest looking elsewhere. When is it misfiring and from what cylinder?

 

Misfires at idle. Changed the connectors on the front 2 injectors. After taking out all the coil packs one by one they all have the same effect which rpm drops loads. Not sure which cylinder it's coming from. How can I test this?

Thought it was given a clean bill of health?

It was aha. It's much better than it was. It's not a constant miss fire it will run fine at 850 rpm approx but you can feel now and again just a slight miss

Misfires at idle. Changed the connectors on the front 2 injectors. After taking out all the coil packs one by one they all have the same effect which rpm drops loads. Not sure which cylinder it's coming from. How can I test this?

 

You're best bet is hooking it up to a conzult and doing the cylinder drop test.

Cylinder drop test? Guessing that's when the cylinders are working?

I will start simple aswell. I will change the spark plugs... what are the best to go with? :)

You're best bet is hooking it up to a conzult and doing the cylinder drop test.

 

All that will have been done when he took it for a health check.

 

I will start simple aswell. I will change the spark plugs... what are the best to go with? :)

 

What is the spec of your car? How much boost are you running? What do you intend to use it for?