There are a few things that can cause this problem;
You may have a bad compressor seal causing a lean mixture issue casuing the misfire.
The MAF may be bad.
There could be other vacuum leaks.
You could have a faulty injector.
The first thiing that is the easiest to try is to dis-connect the MAF and see if it runs better. If it does then the MAF is at fault. You can clean it with MAF cleaner, but the sensor wires are so frail on some sensors you may not be able to do it. Otherwise you will have to replace the MAF and that is expensive, so you don't have anything to lose. I have heard of people using isopropyl alcohol to clean the sensor wires off.
You may just have some common problems that cause misfires like a vacuum leak elsewhere.
I am giving you a link to a diagnostic walk through if the MAF test does not work. To check for a bad compressor seal, you should be able to hear it sucking in air with the hood open and listening closley to the turbo. Also, visually inspect it for sign of leakage as it may puch out some stuff when the blow-off valve opens.
Here is the link;
Let me know if you need anything else and I will get back to you ASAP.
Sunday, January 22nd, 2012 AT 9:16 AM