check engine light issues - again! on 2002 Hyundai Accent

I had two bosch O2 sensors put in my car and neither worked. I was then told that only a Hyundai dealer O2 sensor would work. Well it did for about 6 days. I had the exhaust smoked in case it was not the O2 sensor and maybe an exhaust leak. There was no leak and as far as I know the same code P0133 keeps coming up. This is at AutoZone's test and mechanics full diagnostic test. I'm perplexed and do not want to go back to mechanic without knowing what is going on. Please help!!!! Thanks

3 answers 3 comments
How many miles on the vehicle? The could be an EGR or catalytic converter problem. Either of these issues can trip o2 sensors.
approx. 89,000 miles. what is an EGR? Mechanic even consulted Hyundai dealer mechanic, and parts person at dealer stated that only Hyundai parts on vehicles will work. ????
Dealer parts counter employee wants you to buy their parts not after-market from other stores. No money for them to make if you don't purchase from them. The EGR in a hyundai I believe is called the purge control solenoid valve. Look for #1 in this pic http://images.search.yahoo.com/images/view;_ylt=A0PDoV4p2lBRDAsAbgCJzbkF;_ylu=X3oDMTBlMTQ4cGxyBHNlYwNzcgRzbGsDaW1n?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3Fp%3D2003%2Bhyundai%2Baccent%2Begr%26fr%3Dyfp-t-657%26fr2%3Dpiv-web%26tab%3Dorganic%26ri%3D13&w=385&h=300&imgurl=cdn.2carpros.com%2Fautomotive_pictures%2F198357_Graphic_579.jpg&rurl=http%3A%2F%2Fwww.2carpros.com%2Fquestions%2Fhyundai-accent-2002-hyundai-accent-where-is-the-crankshaft-position-sensor&size=28.7+KB&name=2002+%3Cb%3EHyundai+Accent+%3C%2Fb%3EProblem+Crankshaft+Position+Sensor+4+Cyl+Front+...&p=2003+hyundai+accent+egr&oid=1729cc61a3c84858303b5563b571e46f&fr2=piv-web&fr=yfp-t-657&tt=2002%2B%253Cb%253EHyundai%2BAccent%2B%253C%252Fb%253EProblem%2BCrankshaft%2BPosition%2BSensor%2B4%2BCyl%2BFront%2B...&b=0&ni=112&no=13&ts=&tab=organic&sigr=13c9tmc0k&sigb=13hu8ikkq&sigi=11rhkuorj&.crumb=z7wgX.K4HZS&fr=yfp-t-657
thank you. Your information has been very helpful. I don't know the first thing about cars (obviously), but repairpal has made it easy to understand (as far as my brain will allow, anyway!) Thanks again.
agree with bak 30 seek a new mech that can diag properly
review when last tuned. may not be burning efficiently. regap or replace spark plugs(rec. premium). inspect ignition cables. replace if damaged(rec. performance grade; accel's are good and more cost effective then OEM replacements).
get fuel system clean. use ethanol treatment to 1 tank premium fuel(result will take drive time to show). this will allow fuel delivery to function on point. fuel in air/fuel mix won't be an issue. these are all things you can do yourself(save money).
if prob. persists then you can spend money on different mechanic.