I just bought this 97 monte carlo about 3 weeks ago. I didn't drive it much when I first got it cause i'm in school 4 days a week and car pool in with people. The car was driving excellent, no apparent problems. Now, it still drives fine, feels fine, idles fine until about 10 mins of driving. The car will just shut off. It'* happened at red lights, happened accelrating through a redlight or even a turn. It'* happened during acceleration in reverse also. Hasn't really happened at high speeds though (IE: highway) everytime the car shuts off, I just put it in neutral, turn the key, restart, and drive for a little before it does it again. Sometimes i'll get a few blocks, sometimes it'* the next corner.

It -was- just shutting down at first, now I will get a small hesitation sometimes while accelerating. It'll bog down to like 500-600rpms, shoot back up for a second, than level out and either shut down, or drive fine for another block or so.

I just did the tune-up. OEM plus,wires,fuel filer,air filter, pcv valve. Fuel filter seemed pretty clean, was able to blow through it with no problem. There'* a full 16 gallons in the tank, so I don't think it'* fuel related, not to mention it starts right back up.

Someone told me possible clogged cat, cause the car does appear to be running rich (black soot around the tail pipe, light smell) But I really don't want to gut my cat out, and still have the same problems, and end up fixing a destroyed cat + whatever might have been the original problem.

Any help would be awesome, even a place to start checking..Thanks so much, it'* really frustrating because there'* no check engine light, not even any pending codes when scanned with the lotus.

try unplugging your MAF sensor the car will stumble at first but then level out if it still does it when that is unplugged it'* not your MAF sensor

I forgot to mention that, I tried that the other night when I was having the problem :( It'* the mass air flow...sorry about that.

It'* -not- the mass air flow, can't find the edit button

Crank sensor? Should be easy to check with a decent scan tool.

This is commonly a crank sensor. Downside is there is no way to test it.

Yesterday I decided to replace the ICM since there were a few sitting around my old shop. (commonly replaced the 3.1s on impalas and such, junkyard motors always had'em attached). Problems seems to have gone away, if it comes back I will replace cam and crank sensor, only 20-30$ respectivly and mabye 2 hours to replace both. Stupid PS pump in way of cam

fWIW stalling isn't a symptom of a cam sensor.