well my car has been missing in the higher gears, usually 4th or 5th. it has new spark plugs and wires as well as a complete tune up. does anybody have any ideas on what else i could change or check.
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sorry forgot to mention, this is a 99 gst
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what do you mean by missing? misfiring? missing the gear?

 

misfiring, when you are in 4 or 5 gear and get on the gas you can feel the car jerk it will do it a couple of times and then it will be smooth.
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Have you ever done a boost leak test?

http://www.vfaq.com/mods/ICtester.html

Boost leaks can often cause all kinds of weird things. Check all of your vacuum hoses too. If that doesn't help let us know.

 

i did a boost leak test a while back. im holding boost fine at 13 psi. and it doesnt feel like a its loosing power it just jerks. i thank it has something to do with spark but we just put in brand new ngk spark plugs, and wires. what else could it be
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A boost leak can happen at anytime. If you're still using the clamps that came stock with the car, those may be losing tension. Your sidemount could also have a hole in it. The TB could have a leaking BISS, but most of the time, the piping just slips.
A boost leak check is never a bad thing to do multiple times. The bucking that you're describing sounds like a leak to me, whether it be vacuum or actual boost leak.
Do you have a CEL or any other indications of something being bad?

 

what type of gas are you using in it? if it's not supreme then it'll jerk when you get on it, but i'll have to go with everyone that it could be a boost leak.

 

the gas im using is 93 octane. and no i have no check engine light on. i will do a boost leak test just to be sure but i dont thank that is the problem, otherwise i wouldfeel a drop in power. i will also check all of my plugs and wires just to be sure. anything else i should look at.

 

ive had plenty of boost leaks and never felt a drop in power