Pontiac Repair: 2007 Pontiac G5, chevron techron fuel system, chevron techron fuel system cleaner

Question
Hello, I have a 2007 Pontiac G5.  When I am driving down the road the car is chugging/surging.  It is hard to explain.  It almost feels like a stuttering or surging during acceleration and sometimes during cruising speed.  It feels like losses of power in intermittent spurts.  It does go away when cruising speed is reached for the most part, it is most noticeable during acceleration.  Its not making any noises and there is no check engine light or any other warning lights on.  It does however feel like a slight shake in the front end when it is doing the surge/chug.  I changed the spark plugs to some high end ones a few days ago and it did not help the problem.  Do you have any idea what this could be?  I tried to provide as much information as possible as I am not mechanically inclined.  Thanks

Answer
Hi Steve:

First off if the car has less then 36,000 MILES what ever that is in Kmh it should be a warranty repair, unless it's a maintence item that is the root cause. That said If the car is misfiring then it should trip the service engine soon lamp on unless it's just not bad enough yet. do you feel it in the floor board or the steering wheel or is it just a sensation you have when driving like it's not running right? You could have a bad input sensor to the enegin control module "computer" that's not sending the exactly the correct input and it's throwing off the fuel deliver and spark advance. If you still have the old spark plugs put them back in. DO NOT use anything other then original equipment plugs in this car or any car for that matter. this may have a plugged or restricted fuel filter and it's starving the engine for fuel under a hard acceleration. This was one of the last cars that GM made that still has a fuel filter all the new cars have the flter in the tank this car has one under the car near the rear axle. You may also want to try a different brand of only 87 octane fuel and try a bottle of Chevron Techron fuel system cleaner follow the dosage instructions on the back of the bottle. Good luck :)