OK, let's explain. I start to drive my 2002 GP SE (automatic trans): Green light --> I'am pushing the gas pedal approx. halfway. 1st gear -->engine goes to about 3000 rpm, switches to 2nd gear, then again at 3000 RPM switches to 3rd gear (everything smooth so far) finaly about 3000 RPM swiches to 4th gear, reaches about 3300 RPM and drastically fall to about 1400-1500. I keep the gas pedal still, without releasing Speed is about 65 mph, car horribly lacks of power, sometimes I have 1300 RPM, engine almost idle... Recently I have done the following jobs: engine flush, oil, filter change, trans. fluid change, Injection cleaning at authorized GM shop. Nothing has changed. This is almost new car, it has 27K miles. The problem started couple days after servicing my fuel tank at another shop (not GM). I had a bad fuel smell inside the car, and this guy said I had a hole in the tank, so they fixed it (glue + patch). My friend told me that every tank has a special hole that lets the air flow into the tank when gasoline goes to the engine, and perhaps now I have this hole "fixed". Can someone tell me if this is the problem? If not what could it be? I appreciate any help.
OK, let's explain. I start to drive my 2002 GP SE (automatic trans): Green light --> I'am pushing the gas pedal approx. halfway. 1st gear -->