I have a 2002 Kia Rio (manual). Several months ago it started randomly losing power....sometimes my rpm's get caught around 2k...even if it gets going I have problems when I stop and try to go again...I don't always have a check engine light and every symptom is completely random.... (For example, I'd driven on a particular day 40 miles or so then it lost power out of nowhere...it would idle around 2k rpms or so in neutral but when I'd shift to first it would die but finally putted at a max of 10 miles an hour up a few miles of highway and then all the sudden drove fine again). I took it to AutoZone and it threw code 1166 (rich/lean fuel mixture/vacuum leak etc.)....I have replaced the fuel filter...I took it to a mechanic that changed out a leaky hose into my intake....and that seemed to fix the problem for a couple months until now it is acting up again randomly. I have taken it to another mechanic...waiting to hear back but he has already suggested that it may be my O2 sensor, my catalytic converter and an exhaust problem....yet I have read where people have fixed all this and still have the problem....I called a Kia dealership and the mechanic told me that a possible problem might be purge valves??? or my coil packs could have bad connectors??? He said it most likely wasn't the fuel pump since my problems are sporadic. This seems to be a common problem for Kias....I'm just confused and would like advice. I have no expertise at all about cars and I'm trying not to spend money I don't have...Please, any advice is greatly appreciated. Thanks!