Ok so I thought I had my problem fixed when I replaced my MAF. It seemed to run fine but it just isn't there yet. When I go to accelerate it is misfiring and just not going like it should. It kind of sounds like it's backfiring but I'm not 100% sure. When I get up to speed in each gear and kind of let off the gas it starts firing right and runs fine. I shift to the next gear and it runs like crap again then when I back off the gas and just maintain my speed it kicks into all cylinders and it feels and sounds fine. It was throwing an EGR valve code and a misfire code before. Haven't been able to check it lately.

 

Did it do it after the MAF change or has it been doing it all along? The engine should run without misfiring with the MAF wires unplugged, although it would cause the MIL lamp t go on. Get it scanned & see what codes are there.

 

Before I replaced the MAF it would barely accelerate and ran way worse. It's better not but still isn't right. All the symptoms I described are still happening.

 

Try unplugging the wire connector from the MAF and see how it runs. This will set the MIL and force the PCM to run engine in open loop. If car now runs better, then there is probably a sensor problem. The EGR code can also cause problems, but need code numbers to really know what is going on.

 

You could have a cracked spark plug. If you had a mis-fire code, it would have told you which spare plug was mis-firing. What does that plug look like?