Car ran real rough 40-45 mph 3 seperate times but now is ok check engine light turned off but b4 it did i took to local parts house scan came back O2 sensor bank 1 sensor 1 his parts list shows 2 which one is bad

What type O2sensor did you use ? Aftermarket ? Jeep's ,Chryslers , dodge are picky . WARNING Aftermarket Oxygen Sensors Chrysler part 1 Did you test or just replace the O2 sensor . P0153 Jeep O2 sensor 2 1 Slow Response If you don't have the tools like this guy uses an have the know how it's tough to fix problems like this .

IF the "check engine" or "service engine soon" light is on. You can take it to most any auto parts store to get the codes read.

Better yet would be to find someone with an actual scanning tool to see what all of the sensors are reading.

IF there is no check engine or service engine soon light on then it could be quite a few different things wrong.

A plugged catalytic converter is a possibility. Another item that i ran across on 3 different vehicles within a day was a bad coolant temperature sensor. All 3 vehicles ran fine when 1st started, but then slowly started to "load up" or run rich. REAL rich.

Turned out on all 3 vehicles there was NO check engine/service engine soon light but after hooking up the scanning tool all 3 showed the coolant temp sensor was reading -40°!!

Yup, the computer was being told the engine was at 40 BELOW zero. The computer took that info and adjusted the fuel/air mixture and timing to help the engine warm up.

While the engine warmed up, the sensor kept saying it was 40 below and made the engine run rich.

This MAY be the problem, but without a scan tool it's hard to say.

Hope this helps.

not for sure but it could be your cam sensor. if the check engine light is on then take it to a parts store and they can run a scan and give you more information

could be the egr, injectors, among other things, best to get the engine scanned on a real time scanner, else you are just guessing

newer cars require a scan tool to pull codes, that only gives you an idea of where the problem lies, best is to get a real time scanner with snapshot capabilities, , for examp;e a simple scan may say o2 out of range, but that is just what the o2 is reading, it could still be a leaking injector or a missing cyl not burning right, the o2 will read out of range with nothing wrong with it , so even with a scan you still have to do diagnostics

Go to your local auto parts superstore, and have them scan for the fault code that is making the check engine light come on. Most do this scan for FREE. Take it from there. Could be a simple o2 sensor, or something else. Parts and sensors and relays just stop functioning sometimes. Hope this helps.

The best thing to do is go to Auto Zone and get your Hyundai scanned for a DTC code. That would tell us which O2 sensor has gone bad. You have three O2 sensors and one of them has gone bad, the O2 sensor sends signals to the ecm to control the air fuel mixture so it will not run to rich or to lean which is causing you to fail the state inspection. Good luck and keep me posted on what the DTC codes are, be glad to help.

USA? answering for only here.
fixya computer brain now moves 2009 posts to 2017.
wow.
its a stinking Daewoo ,Suzuki mixed up car. why by
both companies what bankrupt here, why own either or mixed.
wow.
ok, gas cap fail is like 1,000,000,000 posts on world wide.
boring,,,, and my new car even now, says gas cap loose.,

seems you have both a transmission problem and engine.
those misfires are real.
your hubby failed to do a tune up. in last 10 years. oops..
spark plugs and filters>.at least?

The throttle body and sensors love to fail on this POS.

answer. well why are you not testing and scanning
to see what fails, WHILE it failing,
scanning after only catches, 10% of errors, real.>?
scan while failing. and win.

The car is continuing to have problems.
with whaT, NOW? SAY WHAT.

One thing to check is the fuel pressure regulator.
If the diaphram is leaking it will cause gas to be pulled into the vacuum system causing lots of white smoke and extreme rough running.

What code(s) are coming up when scanned?

You said you changed "the" O2 sensor? I believe your vehicle has two O2 sensors. One is located upstream from the catalytic converter and the other is located downstream from it. Is it possible that you changed one and left the other?