I noticed yesterday that the car seemed to be sputtering at about 4-4.5 K RPM at full throttle and under full boost. Especially in the higher gears (4th gear plus)

Does this sound like bad gas or do I need new plugs? It's been about 10K miles since I last did plugs.

 

deff plugs .

 

That's a classic plug scenario, but 10K seems very short for plug life.

 

How about MAF. Do you have OEM air box? Disconnect MAF and try it again. IF the car opens up good then it is the MAF, if still having problems then Plugs. I recommend GT2 plugs, ask Dan at SG.

 

Sold the Gemballa GT700 for a good price. Got a RUf with X50 package and upgraded to GT750. I will post pics soon.

Art

 

One of 3 things

Plugs...Most likely
Maf
Boost leak..possibly bad DV's

Are you getting a CEL? If so pull the codes.

 

Sounds like MAF to me, let's bet on this.

 

I just had the same thing and replaced plugs. But I found I had 2 bad coils as well. Replaced them all and now runs perfect.

 

Plugs....I was hitting stuttering at the same rpms as you. New plugs = no problem anymore.

 

Running the EVO intake with the "fix" have had no MAF issues since.

My gut says plugs.

No CEL BTW.

 

Did you get a check engine light? If yes, what does it say?

 

I will bet its plugs. Good luck, I was only able to get 10k from my plugs.. I went with Bosch FR6 plugs.

 

FR6 LDC or LDU?

 

Most likely plugs. Could also be coil pack. Could also be injectors. I had a couple of bad injectors that created bad sputters @ 4500 RPM at WOT.

 

mine did the same thing a few years ago . tried plugs , and lots of other stuff (costly) turned out to be my MAF .. caused by a oil air filter goat apaper one all has been well ever since