Started a month ago.

If car is cold ( first 5-15 minutes of running ) and I stomp on it, it sounds like popcorn and I go no where. After it's warmed up, it finally behaves like normal. I've had the H/C for 2 years now, nothing like this has ever happened. Could it be one bad tank of gas? Haven't atap'd when cold, but I did 3 runs last week after warmup and LTFT's are 1.3 and O2's are .925

Any ideas?

 

I use 94 octane from Sunoco since day one, 49K ago.

No ideas from anyone? I'm afraid to jump on the throttle now in fear of burning up a piston.

 

I'd be more worried if it was detonating when warm. The solution is obvious, just don't beat on the car until it's warmed up. It takes about 15min of driving for your oil to get up to operating temperature anyhow, even though it only takes 5min for your coolant to get there.