I have a 2000 Monte Carlo ss. I'm on my way home one night doing about 60 mph and my car I driving fine. All of a sudden it gets really loud like a blown muffler and the engine is shaking rather roughly and I notice the odometer dropping and the more I accelerate the louder it gets. It slowed to about 50 and wouldn't get any faster. I make it home and turn the car off when I crank it back up same problem for a few minutes and then it stopped but started right back after a few minutes. It's late so I check it the next day. Cranks right up but still rough idle shaking engine. The next day i tried to crank it and it just turns over all day. So today I get home about 7 30 and just decided to try it and to my luck it cranks but still has loud and rough idle. Please help. I'm tired of working on but don't want a car note right now.

 

Check engine light flashing? If it was me to start I would make sure there is spark from all the coils, sounds similar to when my ignition control modual went out and was only running on 4 cylenders, the other thing to try is unplugging the mass air flow sensor, it if even out and runs fine replace it

 

Yes the check engine light did start flashing. Can't believe I forgot to inclue critical information light that.

 

A flashing engine light most likely means a major cylinder misfire, could be a coil pack, ignition control module, plug/wire, chipped piston, etc. Check to male sure you have spark to all 6 plugs, if you do make sure you have fuel going to all 6 cylinders, if you do then time to run a compression test

 

Bet anything it's the control module. Had that problem before. Spent $4000on new tristar motor rebuilt tranny myself and then spent next month trying to figure out either why it wouldn't start or ran like crap when it did fire up.

 

Run a test on the fuel pressure regulator alao