service engine soon/rough ride help please!

[knoll5150]

Have a very strange situation hope someone can draw some light on: Just today my service enginse light began flashing as I was driving down the highway, on top of it I noticed a vibration coming from the car @ 60 mph, you can really feel it in the shifter. These things all happened at once. When the car's @ lower speeds you don't really notice the vibration. I also notice the exhaust sound sounding weird, kind of hard to describe the sound it makes. Maybe a bad catalatic convertor? (it's a Magnaflow, but I'm not sure of their reliability). The car's a 6 speed manual, and the vibration started instantly out of the blue so I don't think (and pray) it's not a drivetrain issue. The car also seems to
accelerate slower than normal. My cars a 2000 camaro SS
convertible w/65,000 miles. I know it's hard to diagnose the problem until I have a mechanic look at it, just wondering if someone had similar problems with their ride in the past
so I have an idea how much $$$$$ I'm going to be shelling out on this repair? I swear, if I have one more issue with this car (have allready dumped 2K in repairs over the past month! THREE different issues!), I'm going to seriously consider selling it and buying an import, an
older BMW M3 'vert is starting to look good about now!

ps-the engine oil and other fluids are fine, all gauges
(except engine light) are normal.

[2001NBMZ28]

Flashing SES means it's misfiring, could be several things - first thing I'd do is baby it down to your local auto zone and get any code(s) read free if you don't have access to a scanner.

[lvbroham1]

I would check the spark plug wires for anything weird and all the plugs for any cracks on the porcelain part of the spark plug... At least that's where i would start looking...

[Cutlass]

Flashing SES lite means misfire. Its probablly as simple as time for a tune-up. the vibration felt was probablly the engine misfiring.

[Firebirdjones]

SES means it has a code stored. Very first thing to do is get the code from the computer via a scan tool,,,,,it's what it's there for.

This will tell you whats wrong and give you a general direction to start looking.

Don't beat yourself up thinking it's this or that without getting the code first.

[knoll5150]

Wow, you guys are good! All that and it was simply a misconnected spark plug wire... can't believe something like that would cause it to ride so rough! Damn, it's a good feeling knowing it was something that simple...and not something major. Thanks.