Consistently after refueling I start my car and it idles funny ex. "put put put" sound coming from exhaust (noticeably different exhaust note). RPM gauge does not rise or fluctuate radically. when I hit the gas there is slightly less power from engine. typically shortly after I get somewhere safe to pull over it goes away, and doesn't return till i refuel. no check engine light comes on so I cant pull codes.

Current Mods: plenum spacer, JWT pop charger, non resonated test pipes, ARK Grip v2 exhaust.

car is a 2003 with 80k miles. I purchased it bone stock with 65K miles and this problem did not occur. I have heard about leaks from the plenum spacer causing a engine sputter, and Faulty spark plugs or injectors causing this type of issue.

What does everyone think? I know there is a sticky with a similar topic but my issue comes consistently after I put gas in the car. I mean right after, as soon as i start the car before i pull off the gas station property. I use shell gas typically and always use premium. and it doesnt matter if i fill it up or only put a couple gallons in.

 

Vent tube blockage on the gas filler neck????

 

All these mods and no tune?

 

Tune will be happening before christmas. Just making sure im content with plenum spacer, or do I want tto upgrade to actual plenum.

I will look at the fuel vent tube this weekend

 

Huh, I have the same problem, after a recent tune on my Haltech. Plenty more mods on my car, as well. No idea what the solution is, or what is causing the problem.

Here's my thread on the issue

 

just read your thread it sounds like we have the exact same issue. i will be changing the spark plugs, and checking the fuel filler vent hose. then getting a Osiris tune from z1 motorsports. I will keep updating if anything changes.

 

Yeah, if I find a cure, I will let you know as well

 

Well, found out what my problem is, although it won't sole your issues, it might give you a hint: in my Haltech map, the values for the EVAP were all corrupt, including the inactive O2 and the active O2. So, for you, this might mean that you have some issues with your evap canister. Not sure, but at least wanted to let you know.