Hey all. 2002 Sonata, 4cyl. 180000km's. Recently, when starting, the car is very very rough - almost to the point it feels like it will stall out. When attempting to drive, the check engine light comes on periodically, and there is very little power. Again, feels like it will stall.

It's winter here - thought maybe it was a frozen line - but I've run the car for a while and cycled through some anti-freeze, and now have a full tank and it's not cold outside right now. Hesitation comes and goes. Makes me scared to take it on the highway!

Thoughts?

 

The problem could be a number of issues, something as simple as a clogged fuel filter, dirty injectors, or one of the more complicated systems like the mass air flow or throttle body sensors. With the CEL on, error codes have been stored in the ECM. To proper diagnose the problem, you need to have the code or codes read by a scan tool connected to the car's ECM. In the U.S. (I assume the car is in Canada or the UK), many auto part chains will perform this service for free or for a minimal charge. The car is off warranty, so if you have an independent mechanic you trust, you can certainly get the codes read by that person. You always have the option of taking the car to a Hyundai dealership, but you'll likely spend the most by doing so.