Car Jerking please Help!!

Hi, my 1997 Dodge Intrepid 3.3 L has been bothering me. For the past couple months I've tried to ignore it but lately its been doing it more frequently.
When driving at highway speeds ( 50 to 70 mph) my car will randomly jerk pretty intensely. It feels like the engine is misfiring or something. The best way to describe it: it feels/sounds like i hit a foot deep pothole. the tachometer seems to drop for the instant that it does the jerk too and the gas pedal feels weird but then it goes back to normal. the whole process lasts only a second or two but it really doesnt sound like its good.:banghead:

I should also mention I have a bad O2 sensor could that be the culprit?
Any help would be greatly appreciated thank you.

Wlcome to AF.

Have you checked for codes with a scanner or by key dance, post any code numbers??

Last tune up. Have you cleaned throttkle body?

Is it the same when cold engine or warm engine?

How many miles on vehicle?

Its got 120k miles and i dont know any codes off the top of my head. i had the headgasket (s) replaced about two months ago and a couple days after that the check engine light came on and it brought up a code for an O2 sensor and I havent got it fixed yet cause i have alot of other expesnses at the moment. I just hope its nothing major after spending a grand on the headgasket repair

Just got back from the mechanic I had the O2 sensor fixed but they also told me my m.a.p sensor was bad. Can anyone tell me where that sensor is i've been told that its an easy fix and im not throwing away 80 bucks for labor on that part. Anyone know where the map sensor is located on a 97 3.3?

Here is a online manual with a picture of MAP location:

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528006abb8

Look at illustration # 3, it shows location. Also look under Engine controls for MAP sensor it has testing procedure.

Hope this helps