rs695

My 2006 A4 is misfiring when I stomp on the gas between 60-70 MPH. This is a new problem. The CEL flashes for about 20 seconds, then shuts off. Changed the spark plugs yesterday but still having the same problem, with no reduction in frequency or intensity.

Car is starting up no problem and will accelerate smoothly from 0-60; after 60, it gets rough. Had the PCV swapped out about a year ago. CEL flashes only when the misfires start.

Any suggestions?

rs695

Follow up: Confirmed w/mechanic that the old spark plugs were clean, which would seem to indicate that carbon buildup is not the problem. He suggested that the high pressure fuel pump might be the culprit here.

Dolamite

That's a possibility. Has anyone taken a look at the ignition coils in a while? Did you scan the car? You should have a code(s) logged.

rs695

Ignition coils are good. Seem to be left with LP or HP fuel pumps. Or no? Any other culprits?

MikekiM@PureMS

Check your fuel trims first. It could be caused by a lean condition. If the fuel trims are spot on, move your coilpacks around. If the misfire changes cylinders and follows the coils, then replace the coil.