Misfiring codes

My girlfriend's 99 4WD Blazer recently had the 'service engine' light come on. We took it down to Autozone to get it tested and it came back with three errors. The first one involved the misfiring of the cylinders. The second and third just said they were manufacturer's codes and Autozone wasn't grown up enough to be able to handle them or something like that.

The truck runs fine right now (or as fine as it ever did for being a late 90s blazer) so I'm wondering if this is something I should start pumping money (yeah, notice how I said "I should start pumping money", not "she should start pumping money") into or can I put it off til I get the ol Christmas bonus? Has anyone experienced anything like this?

Thanks all!!!! Have a great day!!!!
-Tom O

What were the exact DTC's, (Diagnostic Trouble Codes)? Post them and we can help with diagnosis.

Old Master is right Autozone just gives you the generic descriptions of what the codes mean for all makesand models, and no real specifics. Get the actual codes and post them here or research them on the internet to get make and model specific info.

A misfire code, if left uncheck, could damage your cat-convertor by putting excess unburnt fuel into the cat and overheating and damaging it. I woulnd't leave a misfire code long. Plus your just wasting gas and creating more pollution.