So my Expy has been running rough for a year now with the CEL. It's a 97 with the 4.6.
Replaced the O2 sensor and it cleared up the CEL and passed emissions in CT but still stumbled. A couple of weeks later, the CEL came back on with the code P0304. This vehicle had a tune up shortly before the CEL came on and it started running rough. Well finally it has gotten to the point where it would hesitate and miss really bad between 65 and 70 and the CEL would start to blink. Today I decided it was time to take care of the problem as I love this vehicle. Bought a new plug figured I would start with that. When I got the socket over the spark plug, I noticed that I could turn it by hand. Thought I just was not on the spark plug. Nope, the mechanic must not have torqued it well or it came loose. Put the new plug in, torqued it, buttoned her up and went for a ride. No CEL, no miss, no hesitation, nothing. Feels like it's not even on at the stop light. I even ran it with the A/C on to put extra load on her and she is running beautifully.
Moral of the story: start with the easiest/least expensive thing. Hope this helps others. I will keep everyone posted as to how she's running over the next few days/weeks/months.
Replaced the O2 sensor and it cleared up the CEL and passed emissions in CT but still stumbled. A couple of weeks later, the CEL came back on with the code P0304. This vehicle had a tune up shortly before the CEL came on and it started running rough. Well finally it has gotten to the point where it would hesitate and miss really bad between 65 and 70 and the CEL would start to blink. Today I decided it was time to take care of the problem as I love this vehicle. Bought a new plug figured I would start with that. When I got the socket over the spark plug, I noticed that I could turn it by hand. Thought I just was not on the spark plug. Nope, the mechanic must not have torqued it well or it came loose. Put the new plug in, torqued it, buttoned her up and went for a ride. No CEL, no miss, no hesitation, nothing. Feels like it's not even on at the stop light. I even ran it with the A/C on to put extra load on her and she is running beautifully.
Moral of the story: start with the easiest/least expensive thing. Hope this helps others. I will keep everyone posted as to how she's running over the next few days/weeks/months.
