2002 Hyundai Sonata multiple codes p0455, p0113, p0101, p0301

I have been having trouble with my 2002 Hyundai Sonata, currently it is giving 4 codes p0455, p0113, p0101, p0301. it all started about a year ago with a slow start and has slowly gotten worse over the year.
at this point in time it has a slow start, rough idle, stalls, and will occasionally misfire during acceleration (until i let off the gas, then it will accelerate normally)
on bad days when i accelerate it feels like someone is playing with the shifter because it will go from high idle to low causing the car to jerk

so far as i can tell there does not seem to be any environmental causes hot/cold humid/dry

My interpretation of the codes is that it is most likely the MAF sensor (which i replaced with a junk yard part 3 years ago) but if anyone can see a link between these four codes that is more likely i would greatly appreciate the help.

p0455 - evaporative emission control system leak detected (gross leak)
p0113 - intake air temperature circuit high input
p0101 - mass or volume air flow circuit range/performance problem
p0301 - cylinder 1 misfire detected

I’d focus on codes P0101 and P0113.

The Mass Air Flow sensor also includes the Intake Air Temperature sensor.

So what do you want from a junkyard part?

The misfire for cylinder 1 and the gross EVAP leak are separate issues.


Here’s my take. P0113 and P0101 are probably related as @Tester has mentioned. Your junkyard part may be the culprit or there may be a wire harness or connection issue. I’d break out the multimeter and back-probe the wires to test the output signals to the ECM. You’ll need to have a shop manual or maybe get lucky on a Google search to find the correct output ranges.

The misfire code P0301 can be due to a back spark plug, plug wire, or coil. Swapping wires and coils around to see if the code follows to the next cylinder is a common test. If not ignition, a compression test and leak down test should be considered.

The P0455 should be as easy as a broken or disconnected vacuum line somewhere. It is a 12 year old car, and vacuum lines get brittle and break. The Evap lines run from the gas tank to the charcoal canister, then to the engine.

Thank you for your responses, I ordered a few parts (coils/plugs/MAF) to try and resolve the issues and will be installing them tomorrow and i will let you know how it goes

@brycepower1 The quickest and easiest thing you can do is unplug the MAF sensor and start the car

If it starts and idles much better, then the junkyard MAF sensor was no good

Good that you’re doing a tuneup, also

Well, I’ve got the new parts in, new plugs, plug wires, coils, and a new MAF sensor. it accelerates smooth as silk, however it still is slow to start and has the occasional rough idle bouncing between 500-800rpm then returning to normal idle for a few seconds then repeating. could it be the computer readjusting taking time to adjust to the new MAF? or is their still an undiscovered problem?

before i took it for a test run i reset the codes, although it was a short and relatively slow test run (
5 min, ran into rush hour) no codes reappeared

what do you guys think?

I would disconnect the battery for 10 minutes. This would reset the computer. Of course it will need to relearn your driving patterns.

rpm wandering can be caused b/c the coolant temp isn’t correct. Is the thermostat working correctly, keeping the coolant temp gauge in its nominal position after the engine is warmed up? if the coolant temp is ok, it could be the coolant temp sensor isn’t working.

A dirty throttle body, vacuum leaks, gummed up or broken idle air control valve (if it has one) can cause this symptom too.

Before I started down any of those paths though I’d first correct whatever’s causing the evap problem. You might get lucky and that’s the cause of the idle rpm wandering too.

unfortunately it would appear that the computer was helping the situation not causing it, i stalled 3 times before i got out of my parking spot after resetting the computer, then once more pulling out of my neighborhood, then once more at a stoplight.

i don’t believe it is a coolant temp problem, the gauge reads what you would expect it to, and never rises above half way. i do have an idle air control valve but i have replaced that within the last 5 years as well, and im fairly sure it was a brand new part, although i suppose it could have been a lemon.

The trims may be out of whack due to the old parts. Drive it around normally for a week or so and see if it smooths out. The ECU does need some time to recalibrate the trims to the new parts.

455 and 101 are related to the Evap Emissions… Did you leave the car running when you filled the tank? The 101 code is a bad or leaking Purge Control Valve…

See if your gas cap is OK by having any shop that does Inspections check the cap for the ability to hold a vacume. Most of the times these issues are either a failed component or a break or crack in a rubber vacume line. Clear the codes and see if they return as you may have caused these two by filling up while running…hey it happens. If not…start looking for vacume leaks…its fun.


Went for a drive today, and i did not stall this time, however code p0301 is back, so far the other 3 have not surfaced. i have not filled my tank with the car running but i did take a video of my cars rpm, speed, vacuum, coolant temp, and throttle position with my obdII scanner i cant help but notice that the EVAP test shows up incomplete in the very start of the driving video.

for some reason these videos don’t play properly in WMP i used VLC

idle: http://www.filedropper.com/scr20150207172419
driving: http://www.filedropper.com/scr20150207171744

if it is a leaking vacuum line how would i track it down? i live in an apartment so i can not take apart my car or put it on jacks

I’m not sure about your car, but a lot of cars have two coolant sensors: one sensor that tells the ECU what temperature the coolant is, and another gauge sending unit that tells you (the driver) what temperature the coolant is. If your temperature sensor is easy enough to get to, they’re fairly simple to test with a multimeter (it’s just a thermistor whose resistance varies with temperature).

How many miles on this car and any history of overheating?

Since you’re back to a Number 3 cylinder misfire (and assuming no injector fault) one has to wonder about lowered compression on that cylinder which over time can lead to plug misfires.

As to vacuum leaks, the best method on that (in my opinion anyway) is to connect a vacuum gauge which will determine if a leak even exists. Vacuum gauges are cheap, easy to use, and again in my opinion, invaluable.

You can swap the injector for cylinder 3 with another cylinder and clear the codes. Then see if the other cylinder shows a misfire.

Vacuum line crack or leak detection is a bit of a bitch. First I would get a strong flashlight and use your hands and eyes to look for cracks or issues in the rubber lines… You can sometimes also HEAR the vacuum leak. The third trick to finding these buggers is to use a can of WD-40 or some other spray lube and spray the lines that you suspect of leaking WHILE the engine is running… Pay attention to the idle quality of the engine…if you find the rubber line that is leaking…and you spray it with WD-40…the idle will change pitch and speed. The RPM’s will DROP Down when you find the hole and spray the lube onto the line… Again…SOUND is one of your best weapons in bad vacuum line or general vacuum leak detection. You will be using ALL of your senses on this one…You should have luck in finding the culprit.

In this instance of your Evap Emissions codes…the vehicle THINKS that your gas cap is LEAKING…I.E. NOT making a perfect and Air Tight seal on the tank… SO its either your Gas Cap…the rubber lines associated with the tank…any plastic valves assoc with the system…the rubber tank filler neck…all these things need to be checked.

Good Luck…this can be fun sometimes. IF you have cleared the codes and the Evap Codes have NOT returned…it may have been a wierd circumstance that caused the issue…the gas cap not being on properly etc… See what you get…it may not be an issue at all.


I think it’s going to be difficult for you to figure this one on your own given that your situation dictates you can’t remove engine components or take anything apart to visually diagnose the problem. I’d focus on determining what is causing the evap problem first, as it will likely be the easiest for your shop to solve and fix, and might be contributing to the other symptoms. If not, the good ideas posted above will be next. It would make sense at that point to test the vacuum system, that’s fairly simple to do. But I expect the problem will turn out to be something besides the vacuum system, either the throttle body or IAC is gummed up, or you have an ignition system or engine-mechanical problem. Best of luck.