Just wanted to see if anyone else has experienced this problem.

I have a 2005 (06/04) Scion xB with 85K on it. Every now and then it will hesitate. This is even with my foot on the gas. Basically RPMs will drop. If I am sitting still it will stall.
It did it to me earlier and it is 90 degrees out.

At 83000k I replaced the Air filter (put CAI back [Though it was doing this before hand]), the oil, the spark plugs, and the fuel filters. I also at the same time put in injector cleaner. I have also previously replaced the MAF for this reason also. It used to be a lot worse, the car would buck basically. When I went to replaced the plugs I noticed that I had not tightened down a coil tight enough last time and it looked like it was arching. (The plug, boot and cylinder were rust colored. as well as the plug having a lot of soot on it.

Anyone seen this, or have any ideas?

 

I had a similar problem and ended up disconnecting the battery for 10 mins to reset the computer. It was fine after that. Don't know if it would work for you, but it is worth a shot.

 

No hesitations yet. My only complaint so far is the sticking throttle body. After it idles for awhile after deceleration I have to tap the pedal to un-stick it. Really annoying.

 

Removing the ECU fuse works too

The problem is, it does it once in a blue moon. and I drive my car a good 50 miles a day.