Fault finding idle + acceleration issue

[Timmos]

Hi guys,

I've had a few issues with my car lately, i recently noticed an annoying shudder, huge delay between accelerating and when the car actually responds, terrible idle to the point of it practically dies and returns normal function but with an engine warning. It feels as if each time i accelerate the car is going to stall. now i've had a few suggestions, o2 sensor, MAF sensor, control arm, engine mounts, cracked head.. the list goes on.

My question is, rather than just start replacing part after part... spending more money than i would at a mechanic (which really defeats the purpose of working on your own car) where do i start in fault finding?

[wortus]

I'd check to see what error codes are logged and then check/replace what it is indicating has a problem. If you can't do that then start with the throttle position sensor, then remove and check each spark plug lead resistance is within spec and then check the spark plugs, air cleaner, fuel filter, fuel pressure.

[Timmos]

Thanks Wortus, i couldn't find the error code anywhere. but I went n saw my mate today whos an apprentice mechanic, he seems to think i cracked something when i was putting in the new spark plugs? does this make sense to anyone... if so what is it.

[acarmody]

Probably the spark plug itself.