lexpilot

Hey guys, my ES #2 is acting up a bit. When at operating temp and cruising steadily at 60 or so I get this surging and hesitating for a second or two ever once in a while. It feels like when you hit standing water puddles. Only for a couple seconds though and more often after I stop for a couple minutes at a store or something. I'm thinking that while it is shut off for a bit the upper end gets heat soaked and makes it more prevalent. I have two of these exact cars and have swapped the throttle position sensor and the EGR position sensor. I did adjust the throttle/trans cable as it was loose causing some low end surging. The trans was shifting early then popping between low and second til I got going over 10 mph.
The torque converter is staying locked up so I know that is not it.
I had it put on a Snap-on Verdict scanner for the O2 sensors and engine monitor but it was not definitive.
I am leaning towards an intermittent O2 sensor though, maybe a wire?
I hate to swap the O2 sensors cause I hate to disturb them.
What do you think?

Lex
PS: just uploaded pics of them on my album

mdbrown

When were the spark plugs last changed? You might look at the plugs/wires/coil.

lexpilot

Plugs and wires about 20K miles ago. It runs fine until 20 min into a hwy drive then it seems to happen at 2250 rpm. And then it lasts about 2 seconds or so. I can't make it come and go with the gas pedal like a bad position sensor I had a couple years ago on #1.
Swapped the O2 sensor near the firewall tonight and will try it tomorrow.
Also I'm wondering if anyone has had any luck with any of the OBDII software with a laptop monitor systems?
http://www.autotap.com/product_learnmore.asp
I would like to see what is going on when this happens. I know some log all the sensors in real time. That would be cool if they actually work and refresh fast enough.
I'll let you guys know when I figure it out.
Lex