I have a 98' w/ 5.4 V8, just hit 100k. I am having this annoying problem on acceleration. Say your getting on the interstate accelerating from 45 to about 65, engine starts shuddering similar to running a lower octane gas. Stomp on the gas and it clears up and accelerates normally. Sometimes I get the check engine light that eventually goes out. I usually get the problem in the 45 to 70 mph range. Never had this problem until recently.
I have searched the threads and I am at a loss for a starting point. I am due for a plug change but this feels like a sensor problem. Thanks in advance.