99 park avenue bucks and hesitates for 10 seconds then runs fine

[rahhbaby]

Hi
My PA bucks and hesitates and has a loud sputtering noise from back of car and feels like car is not getting gas as I push pedal for about 10 seconds like once a day then runs fine. I thought it might be bad gas there is no check engine light. I took it to Buick dealer they had it for 5 days and got it to act up on 2 occasions but could not get it to duplicate. They told me to come get it and bring it back when it acts up more consistently I took it to the gas station since the tank was almost empty and added premium gas and gas treatment bottle and drove it around. It acted up but just for like 3 seconds, much less than before. Should I be concerned to drive it or could it be just bad gas?
Btw had spark plug and wires And ignition module all changed in last 18 months
Thanks

[Greenblurr93]

how do the other service items look? air filter? have you ever had the fuel filter changed? ever done a upper engine cleaning?

[rahhbaby]

It's been awhile since I changed the air filter never changed fuel filter and not sure about upper engine cleaning thanks

[Greenblurr93]

most manufacturers recommend an air filter every 12-15k miles.. upper engine cleaning can work wonders for restoring your vehicles performance.

[GMCustomerService]

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel (see “Fuel” in the Index). Poor fuel quality will cause your engine not to run as efficiently as designed. You may notice this as stalling after start-up, stalling when you put the vehicle into gear, misfiring, hesitation on acceleration or stumbling on acceleration. (These conditions may go away once the engine is warmed up.) This will be detected by the system and cause the light to turn on. This can also be found on page 2-80 of your owner’s manual.

The 8th digit of your vehicle identification number (VIN) shows the code letter for your engine. You will find the VIN at the top left of your instrument panel. (See “Vehicle Identification Number” in the Index.)
If you have the 3800 V6 engine (VIN Code K), use regular unleaded gasoline rated at 87 octane or higher. If you’re using fuel rated at the recommended octane or higher and you hear heavy knocking, your engine needs service. But don’t worry if you hear a little pinging noise when you’re accelerating or driving up a hill. That’s normal, and you don’t have to buy a higher octane fuel to get rid of pinging. It’s the heavy, constant knock that means you have a problem. If you have the 3800 Supercharged V6 engine (VIN Code 1), use premium unleaded gasoline rated at 91 octane or higher. With the 3800 Supercharged engine, in an emergency, you may be able to use a lower octane -- as low as 87 -- if heavy knocking does not occur. If you are using 91 or higher octane unleaded gasoline and you hear heavy knocking, your engine needs service. You can also find more information regarding fuel starting on page 6-4 of your owner’s manual. If you have further questions, or if the concerns continue, please feel free to contact me. Thank you.

Tricia, GM Customer Service.