hey everyone, new to this site and lookin for some help... workin on sisters '96 1.9. 2 days ago she had the oil and air filter changed and the next day had troubles. she was driving it and then all the sudden started running like crap. had no power, felt like it was missing bad and would idle very rough and car would die... i've pullled timing cover and everything lines right up. all plugs have good spark, clean MAF, IAC , checked for vac. leaks, checked intake-no leaks... OBD II and throwing NO CODES. when at an idle (very rough and shakin like crazy!! ) the timing runs between 12 and 23 degrees advanced and is pulling between 10 to 20 lbs. vac., but both timing and vac. are all over the place while at the rough idle.. you can also smell exhuast while sitting in the car. also sounds like detenation ping when you rev the motor and motor seems to smooth out when at higher rpm's. i have been all over this motor and can't figure out anything!!! anyone had troubles like this before??