Misfiring

20

Asked by Jun 11, 2014 at 10:05 PM about the Hyundai Sonata

Question type: Maintenance & Repair

Hi there, I am from Australia and I have a 2005 NF Sonata Elite with a 3.3 v6 engine. For as long as the past 3 years, a check light has been constantly on, stating there is an issue with the 02 sensor. For most of this 3 years, this has not caused any issue and a mechanic once told me, unless your fuel economy gets worse, I wouldnt replace the 02 sensor as it is an expensive job and is probably just a electrical fault. Needless to say, on pulling out of a shop last week onto a highway, i put my foot down to be able to merge properly and my caar lacked power, made loud metalic sounds and the check light flashed. Took it straight to the mechanic, my car is now misfiring on cylinder 1 3 & 5. It is shuddering at all times now and the check light is constantly flashing. I recently had the sparks replaced as per the log book servicing guidlines. I hadnt experienced this misfiring issue before. It is currently down at the mechanic, they found a small air leak in the exhaust system that they claimed could have been the caause of the o2 sensor issue, they said essentially 'suck it and see' and come back as soon as a check light comes back on. To my surprise the check engine light didnt come on within the first km, as is usually the case after having the codes cleared, with i would assume, an 02 sensor code. But my car still had a slight tinny sound and lack of power, especially noticable when the foot was put down and it changed back a gear or 2. Shortly after, the check light was back flashing again and running rought and shuddering. I took it right back to the mechanic and the same misfire codes are coming up. They have had it 2 days now and are replacing the 02 sensor, despite that error code not coming up again on the test drive mentioned. I read a previous post which talked of the timing chain slipping a couple of notches, i also saw a post where someone had Intake Oil Flow Control Valve (24355- 2G000) replaced by a hynudai service dealership and that seemed to fix his issue. I am just a little concerned that the mechanics are replacing things because they just dont know what the problem is hoping it is the cause. The issue with this is that it may not fix the problem, but I still have to pay for it and the price will begin to add up.

5 Answers

61,115

Have your catilac converter checked,may be thats what that o2 sensor was trying to tell you,check your catilac converter may be stopped up.

1 out of 1 people think this is helpful.
61,115

When they stop up you here a rattle.

1 out of 1 people think this is helpful.
20

The mechanic says that the back ones were relatively clean, although some black soot was present, consistent with the engine running rich. They have stated that the front ones are connected to the manifold and therefore would cost thousands to replace. Given that the back ones didnt look too bad, the assumption is that the front ones hopefully wouldnt be too bad either, although i do realise that the front ones would take the bulk of the soot or unburnt fuel but would also expect some flow over into the back ones, which they appear clean... this is my rough theory anyway. I am aware that the cat converters may require replacing, but at such an expense with no guarentee that it will solve the issue, I am inclined to look into cheaper potential issues first. But yes if it comes down to it... I will have it done.

1 out of 1 people think this is helpful.
20

The rattle occurs when I put the car under load, when the check light was flashing constantly, under gentle acceleration, the metallic sound wasnt really present but when i accelerated a bit harder or went up a hill it would. I wouldnt say that it is a rattle, which would imply a loose or broken part, but rather a noise of inefficient, uncoordinated or not in sequence moving parts of the engine.

1 out of 1 people think this is helpful.
61,115

Yes, that metalic sound is raw gas going into your converter,your o2 sensor is telling your ecm it need,s fuel,meanwhile your caty is having to burn up all the raw suit gas,and that is why it,s running this way.Yes it,s expencive but, it will get worse as time go ,s on. Good luck with this.

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

  • Misfire 1 answer

    I changed spark plugs today due to a cylinder 3 misfire. Start it up and idled badly and stalled. I took the air box off and it idles almost normal but as soon as i put it vack on it stalls. I also...

    2017 Hyundai Sonata GLS

    -

    Maintenance & Repair

  • What would cause a 2003 Hyundai Sonata 4 cylinder to misfire and die? 1 answer

    For no apparent reason when driving it will misfire and die. We replaced the fuel pump and fuel filter, spark plugs, wires and ignition coils and it still runs rough and misfires. Any suggestions? Th...

    2003 Hyundai Sonata

    -

    Maintenance & Repair

  • 302 cylinder misfire 1 answer

    my 01 sonota gls six cylinder has a po302 misfire code. real rough idle and is worse in gear. also there is a weird pop sound from the engine...i changed the coil pack and it didnt change..any suggest...

    2001 Hyundai Sonata GLS

    -

    Maintenance & Repair

  • Shows all cylinders misfiring 2 answers

    At first it didn't sound right to me but no engine light. Then the engine light came on took it to my mechanic his reading said all cylinders misfiring, The cylinders are all new the plugs and wir...

    2003 Hyundai Sonata Base

    -

    Maintenance & Repair

  • misfireing 1 answer

    i OWN A 1999 ACCENT, I DID A BASIC TUNE UP PLUGS,WIRES,OIL AND FILTER AND NOW IT SAY MY NUMBER THREE CYLINDER IS MISFIREING.IT IS SLUGGISH ON TAKE OFF AND AROUND 65 TO75 MILES AN HOUR WHAT WOULD CAUSE...

    1999 Hyundai Accent 2 Dr GS Hatchback

    -

    Maintenance & Repair

Sonata

Looking for a Used Sonata in your area?

CarGurus has 51,625 nationwide Sonata listings starting at $1,300.

ZIP:

Search Hyundai Sonata Questions

Hyundai Sonata Experts

#1 toDumbToNotKnow
toDumbToNotKnow
Reputation 1,400
#2 Tom Demyan
Tom Demyan
Reputation 1,220
#3 dandyoun
dandyoun
Reputation 970
View All

Related Models For Sale

Used Hyundai Elantra
610 Great Deals out of 55,144 listings starting at $895
Used Honda Accord
888 Great Deals out of 82,090 listings starting at $999
Used Kia Optima
529 Great Deals out of 31,520 listings starting at $2,361
Used Toyota Camry
1,086 Great Deals out of 98,044 listings starting at $1,250
Used Nissan Altima
1,099 Great Deals out of 83,208 listings starting at $670
Used Ford Fusion
1,105 Great Deals out of 78,360 listings starting at $1,250
Used Chevrolet Malibu
1,081 Great Deals out of 85,119 listings starting at $1,995
Used Honda Civic
705 Great Deals out of 77,526 listings starting at $1,200
Used Nissan Maxima
359 Great Deals out of 25,313 listings starting at $1,400
Used Hyundai Santa Fe
301 Great Deals out of 16,529 listings starting at $1,995
Used Toyota Corolla
924 Great Deals out of 74,282 listings starting at $1,500
Used Hyundai Genesis
119 Great Deals out of 2,623 listings starting at $5,995
Used Chevrolet Impala
799 Great Deals out of 34,708 listings starting at $799
Used Mazda MAZDA6
192 Great Deals out of 16,653 listings starting at $1,995
Used Hyundai Sonata Hybrid
36 Great Deals out of 3,313 listings starting at $6,499