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2003 Hyundai Elantra hesitates/hiccups

my 2003 Hyundai Elantra is doing, it will drive fine for a while, then it will start to hesitate a little bit wether it’s in park or I’m going 60, when the hesitation happens it will like hiccup and it’ll do it for a while then go back to normal, then when I park, it’ll have an erratic idol for a while but then it becomes totally random when it might hesitate/stall and die or repeat, but no mater what it’s doing it always seems to bump in to gears and sometimes it’ll slip down a gear, I’ve got my codes pulled and I got 5 codes, every single one was for my O2 sensor, which I replaced as well as my spark plugs and throttle position sensor cause I did get one for that a long time ago, but none of them fixed the problem

Your properly working O2 sensor gave you 5 codes telling you that it detected something was wrong.

If we new what those 5 codes were we might be able to help.


It gave me po038 3 times and p0136 twice otherwise that’s the only codes other then the throttle body sensor (which I replaced)that it’s recently spit out, I also Live In a cold part of Alaska and it’s usually about -20

the p0038 is for the heater control circuit which warms up the O2 sensor. Bank one, sensor two; i.e. the one after the cat) Could be a faulty O2 sensor heater coil, but more likely a break or short in the harness for the sensor. The p0136 is for the same sensor, but that problem is for the O2 sensor signal itself. It can’t read the O2 sensor signal You’re going to have to check the harness between the engine computer and the sensor to make sure you are getting good low resistance between the two on all the wires, and no shorts.

That sensor is involved with the air fuel mixture so if it wasn’t working you could get drivability problems. Do you notice the problems more w/a warm engine than a cold engine? If so, that’s what you’d expect if the sensor’s signals weren’t making it to the ecm.

You have to consider a faulty cat with these codes too.

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What would a faulty cat do? My exhaust melted just after the cat one day while driveing and I’ve had it jerry rigged with tape (exhoast tape) and tie wire for more then a year now and it’s never been a problem, but I did look it over and there doesn’t seem to be any major leak, and could it just be the clip for the O2 sensor? The plastic lock broke off when I was swapping them cause the cold, but it’ll still stick on there tight. When my engine first warms up almost every time it will hesitate/hiccup repeatedly until it’s warm, then it will hold an idol pretty steadily but will still stall, then no matter if it’s warm or not when I drive it it’ll eventually start to hiccup, like it’ll loose all power and the pedal does nothing but it’ll always come back while driveing, it’ll also slip out of gears sometimes, and it’ll have a higher rpm while driving afterwards even though it’s shifting properly (it’s an automatic)

Drivability problems most noticed at higher speeds & engine loads is one. A faulty cat can overheat and damage the floor of the car or other parts of the exhaust system is another. You can google to find the other common symptoms of a faulty cat. Sometimes the ceramic matrix breaks off inside the cat shifts around and that results in intermittent symptoms, car runs fine at time, then starts to stutter and stumble and have reduced power for no apparent reason. Modern engines for the most part simply don’t run well if there’s any air leaks between the air filter and the end of the tailpipe, so if you know you have leaks good idea to address those as they me be contributing to your symptoms.