2001 Buick Regal 3800 V6 coughs on accelleration?
The engine goes "rrrrrr-cough-rrrrrr-cough-cough-rrrrr" (with the rrrr as normal) upon acceleration, from a start or full speed (it isn't related to low or high RPM). It isn't related to cold or warm engine. Engine has 145K miles. The Check Engine code says knock sensor, which is accurate. I increased the octane on fuel: no effect. I don't think there is a problem with the ignition components (spark plugs and wires replaced 5K ago...two of which are the hardest spark plugs I have ever replaced), or regular maintenance (filters, fuel system). I checked MAF: appears in good condition, voltage is normal (4.9 - 5 volts). O2 sensor was replaced 5K ago.