I have an 02 sport 4.0 with auto trans and haven't had any codes or cel but have been having a stumble or surge while driving highway speeds. (60-70) I first thought I had gotten some really crappy gas and that still may be true but I started searching the forum and this is what I came up with.
After treating the fuel and no longer filling up at the suspect location, stumble was still there. Not major just a seat of the pants sensation and maybe couple hundred rpm drop. Having read up on the torque converter lock up issue in the 32rh I added an anti-shudder treatment and dont think that was the issue either. ( I have about 20k on a fluid and filter change and it has been shifting flawlessly - I also have a deep pan on it for the extra quart capacity) I wasn't having any stalling or dying issues so I didn't want to replace the crank or cam sensors. I wound up replacing the TPS and IAC to see if that would solve the problem and it seems to have corrected the issue. I still think I feel a faint surge at highway speed but it could be in my head.
My question for those who have experienced something like this, should I go ahead and replace the engine management sensors like the MAP or crank or cam sensors? Would it do any good or would it just be spending money that isn't necessary? I normally don't replace anything unless its an upgrade, because I don't believe in throwing parts at a problem but remember, I am not getting any codes at all.
As a side note, I have noticed a 1.5 mpg increase after the two sensors were replaced. Nothing else has changed. Could my TPS have been bad and not thrown a code? Any insight would be appreciated, thanks.