04GTLIB wrote:Matt.
Pretty much have the same issue with our 04 GT.
I've had the injectors removed and ultrasonically cleaned, plugs replaced, 02 sensor replaced twice, AVCS banjo filters removed and the solenoids cleaned, had a workshop check for vacuum leaks, replaced the air box and MAF sensor and I've swore and cursed at the fuc*ing thing till I was blue in the face and no one can tell me what the problem is or how to fix it.
So I'm real keen to hear if you do find out what's causing this particular issue, cause I've seriously done my head in trying to figure this one out
Cheers,
Rusty.
If you can get some logs with a tactrix cable then we can lend a hand... the OP (ie matt linegar) sounds like running lean/usually caused by a boost leak. If you connect with a laptop we'll quickly see if that's the issue.
It's very unlikely to be the AFR/O2 sensor, because the car won't go from idling badly to idling well of a sudden.
You have to think "why is it good at above 2000 but not below?", which also makes the plugs and injectors very unlikely.
Get in there and log for what's changing when you click over 2000, what are the AFRs like in both regions, other symptoms - how does it drive etc. If it's a boost leak a simple Learning View should show it up.
The issue is usually pretty simple to fix, but it can be a real test of character trying to find what it is. Good luck and if you need more advice/details let us know!