c5 hesitating
I have changed the fuel filter and just did the ls1 to ls6 pcv mod, thinking it was a vacuum leak in the pvc system neither of these helped. any thoughts?





The U series tells me that you had some serial data buss COMMUNICATIONS issues.
There are most likely some other problems that your not seeing. Do you see any crazy messages or gage readings on the IPC???
CLEAR ALL THE DTCs
When you experience the issue, without turning off the ignition, clear any messages in the DIC by pressing reset and then go right into reading the DTCs. Post what you see there.
Bill
I changed out the spark plugs and wires and reset all the codes. Took her for a ride it is definitely running better not doing it every time now but it did happen three times in a 5 mile drive. There were no code anywhere when I got done with the ride





Get a Fuel Pressure Gage that you can monitor with the hood shut. Monitor the fuel pressure during the stumble events.
What is the battery voltage reading at the time of stumble?
Are there any messages on the DIC when the car falls on its face?
Bill


