Simon1

What was your trap speed before and what is it now?

sailing220

Side note - I wouldn't waste your money on the spark plug "if you screw up" removal tools or whatever they are selling now. At 15k miles you should not have much carbon buildup locking the plugs in, they should pop right out.

gman73

Have you cleaned you T.B lately?

MoneyShot

maybe that is the problem. are you tuned to run premium? time to quote the manual

"Octane recommendations:
Your vehicle is designed to use
“Regular” unleaded gasoline with
pump (R+M)/2 octane rating of 87.
We do not recommend the use of
gasolines labeled as “Regular” that
are sold with octane ratings of 86
or lower in high altitude areas."

"Fuel quality:
If you are experiencing starting, rough idle or hesitation driveability
problems, try a different brand of unleaded gasoline. “Premium” unleaded
gasoline is not recommended for vehicles designed to use “Regular”
unleaded gasoline because it may cause these problems to become more
pronounced. If the problems persist, see your authorized dealer."

also have you done any performance mods recently to your car? make sure your car relearns its fuel trim with every new performance mod you ad. more manual time...

"the engine must
relearn its idle and fuel trim strategy for optimum driveability and
performance. To begin this process:
1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park) (automatic transmission) or the neutral
position (manual transmission), turn off all accessories and start the
engine.
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16 km) or more to
relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle
quality of your vehicle may be adversely affected until the idle
trim is eventually relearned."

i would make sure you follow all of those to a "T" and make sure you gradually hit WOT at least once in the relearning phase, but in first or second gear. also a tune up, maybe some sea foam, an oil change with name brand oil and filter, a tranny fluid exchange and get a compression test, that would be a big one for me.

Simon1

It's a figment of his imagination.

DLZ314

I run mine as a DD and the car "learns" my commute, as it does that the car slows. I have to re-load my tune occasionally.

If you don't have a tuner: disconnect your battery, wait 30 minutes, reconnect the battery and drive like McQueen....