Question"Hello, my 99 a6 quattro 2.8 non turbo is acting up. I replaced the MAF twice now, and the problem is not so severe now, but when i give it a little more gas than i should(floor it) or just floor it leaving a stop, the car will hesitate, sometimes make a popping sound from the engine compartment, and then go to normal after 1-4 seconds. My engine light is not on, it has only been on once before for O2 sensor, but i dought that is what is causing it. What could the problem be? it has only started happening recently, Thanks."
Answerhello.
Try to clean and adapt throttle plate, on many 1.8 engines this happen if it's not clean. Also, think what's O2 sensor for??
O2 sensor monitors exhaust and send the signals to the ECM - ECM adjusts fuel / air mixture based on temperature and readings from O2 sensors. So, (example)what will happen if your O2 sensor send bad reading , - ECM cuts or add the fuel ---- and this also may cause car to hesitate....
I'm not saying new O2 sensor will fix your car , but on my own I will start with fixing check engine first.
good luck Greg
