ym42

A while ago my 06 GT with 140k miles aquired a misfire ( confirmed by a code and flashing "check engine" light ) that ONLY happens at WOT acceleration >4.5K RPM. I also notice some serious pinging around that RPM at WOT as well. Any ideas of its origin? Car feels restricted and losing power above 4.5K, which is probably due to above-mentioned misfire... Is there a connection between pinging and misfire? Fuel injector - lean mixture?

go-part

http://www.engine-misfire.com/

How old are the ignition components?

Have you tried getting the check engine light code read?

ym42

Took the scanner to the car today, and what I found was pretty interesting/suprising. My problems seem connected to the fuel system. Engine codes are Misfire Cyl 5, Misfire Cyl 6, Multiple Cyl Misfires, but whats more interesting was that I found in freeze frame data - that the engine running in Open Loop during the code. The coolant temp was normal operating, RPM 4300, fuel trims looked normal. All the components are original at 137k miles...