Spark Plug misfire no fire? 93 TT
 

Hello,

I noticed a month ago that my 93 Twin Turbo was acting a little rough and would struggle a little bit in lower rpms, also it would idle a little roughly sometimes. I took it to Tunex(I am no mechanic) to get inspected and emissions and asked them to look at it for me and they said one of the cylinders (5th?) wasnt firing or was misfiring. Anyway they said they tried a new plug and it wouldnt fire at all.
From reading some of these posts Im guessing they didnt put a NGK plug in, especially cuz on the drive it home it was even rougher and slower! The guy said nothing came up on the computer and he thinks its probably some vacuum/hose issue? Any input would be greatly appreciated......Also my car only has 53k miles and has sat all winter so possibly the plugs have never been replaced in its life. Also my rear tires are balding and they still passed it haha