I have had my hyundai elantra 96 AT for nearly 6 years now. At the moment im driving on Overdrive because the gears wouldn't not shift to 4th gear . Using the OD i keep the gear from slipping into 4th gear so i have been driving on 3rd gear till i get enough money to fix the transmisssion.

THe major problem is my hyundai elantra has been misfiring , not idling right each time it is raining , wet roads and melted snow. I have change my coil pack, wiresets and spark plugs.

I haven't change my O2 sensors because i am broke at the moment. I really want to know what is the major problem that cause the engine misfiring , not idling right EACH TIME IT IS RAINING , WET ROADS and METLED SNOW.. PLease help.. I went to autozone , they did a diagnose on it telling me i need a tune up. I m pretty sure tune up would not resolve the problem. Would a bad alternator cause my engine misfiring , not idling when i am driving in the rain , wet road and melted snow. Please help me guys. This is my only car i have right now

 

so this only happens when it is wet? check for vacuum leaks, how does the engine run when it's dry?

 

Exactly , only when its wet , raining heavily , melted snow, this misfiring and idling not consistent. THE ENGINE RUNS SUPERRRRRRRR when it 's dry. Since i change the coil pack. I just need to step on the throttle a little bit and i can feel a better response. Vaccum leak.. ..I will surely asked a mechanic to check on that. I have asked around about o2 sensors going bad, most of the mechanic says o2 sensors wouldn't not cause misfiring or idling , o2 sensors just control the emission . I check my computer brain which is under my driver side. It is fine no loose wire's or anything. Any other suggestion?

 

how about this, make your own rain, use a hose or a water sprayer bottle, spray it on individual electrical parts and see which one it affects. make sure you do it on things that rain or water would catch if it rains. hope that helps