96 contour 4 cyl duratech vin3, 108k miles
Acceleration feels extremely sluggish between 35-50. Also, between 45-50 the engine seems to.. stumble real bad. I can feel it skipping. The problem seems to be avoided if I floor the gas and accelerate up from 20 or so rather quickly.
Also, on occasion the car will idle roughly after it's warmed up sitting at a traffic light. It isn't completely uncommon for it to stall at this point. I've also had problems stalling while swtiching between drive and reverse.
Lastely, the temperature gauge isn't working [it never rises from the lowest point], but the heat works fine. I'm fairly certain it's just the temp sender, but I figured it's worth including.
The oddest part about the car is that these problems seem to come and go. I can't really explain it, but it seems like it has some bad nites and good nites.
Recent work:
-replaced IAC valve [past week - seemed to solve most idling problems, but not all]
-changed oil [past week]
-replaced battery [past month]
-fixed head gasket leak [month or so ago]
-changed spark plugs, filters, trans fluid [@100k miles]
CEL CODES:
-P0420 [bad cat, the light comes and goes]
-I'm pretty sure I had a light coming and going reporting that there was a misfire in cyl4 a while back. I think it got cleared when the plugs got replaced at 100k, but I'm not certain.
I think that's everything. I'm gonna try to clean the maf sensor in the next couple of days. Could it be the bad cat causing all the problems? If so, how complicated of a task is it to gut/cut it out? It really isn't too big of an issue legally here in Michigan to ride without it.
Any help would be greatly appreciated. Thanks!