Really rough idle need help!!

[Duane78]

Hi everyone really need some help please
Try and keep this short, my lcr had both the abs light and traction light permanently on local mechanic plugged it in and was told abs pump sourced another pump and had it fitted to still have the same lights. Since then I have got it down to just the traction control light. I have plugged it in and it now only says steering angle sensor. Then 3 days ago I started the car and it started running really rough high revs then almost cut out, I plugged it back in and said maf sensor so unplugged maf while car running and it ran fine I have now changed the maf to a new Bosch maf. Started car back up and its worse high revs and then it does eventually cut out. I have noticed I slight split in pipe under manifold just on where it connects but surely that wouldn't make it that bad. Car has never skipped a beat in the 4 years of owning it up until those 2 dam lights appearing 4 weeks ago please someone point me in right direction thankyou all in advance.

 

[mty12345]

Hi mate, your post is in the FAQ's rather than the main section. Layout is confusing, but if you scroll right to the bottom of the main page, the new thread box is there. The obvious one at the top is infact for the FAQ section.

As for the issue, replace the split pipe and see what happens. Intake leaks will cause rough idle and running, not usually as bad as yours sounds, but you need to sort that before you chase other stuff.

Unplugging the MAF is a bit of an old wives tale really. It disables all fuel trims and makes the car run in open-loop mode rather than closed loop. So it's basically guessing at the fueling and ignoring things like intake leaks because it has no way of measuring it. Because of that it's no real help in diagnosing anything and usually just results in replacing a MAF when there is nothing really wrong with it.