Posted: 8/17/2013 10:58:43 AM EDT
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My g/f's 2006 Hundai Sante Fe started running and idling rough then the check engine light came on.
I pulled the codes, P0430 and P0302. I know the first one is a inefecnecy of catalyste below threashold bank 2, the second one is a misfire detected. Where do I start to look for the problem? |
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My 2003 Tiburon started throwing similar codes (banks 1 & 2 lean, upstream cat bad) and occasionally idling very roughly.
After playing around with sensors for what seemed like forever it turned out to be a bad MAF sensor and bad IAC valve. Can't say your problem is the same but the symptoms sound familiar. |
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Agree to clean the MAF first. I used cleaner and replaced the air filter first. It solved the problem for all of a month before it went bad again. Not sure if the two were directly related but after replacing the MAF the idle started going nuts at stop lights ( bouncing up and down from 1k-3k). Replaced the IAC valve and all better.
Think all told it was about $175 in sensors. Check rockauto.com |
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Quoted:
thank you both. I wanted to get oil change stuff for my car tomorrow so I will pick up MAF cleaner while I am there. Get a couple cans of CRC MAF cleaner. Why a couple? It works awesome on pistols, especially polymer. The IAC valve is basically a 2nd throttle body that opens up a little bit when the car is at idle and the main TB is fully shut. Some throttle body cleaner shot into it is usually enough to blast the carbon out of it and get it running again. Unless it's an electrical issue, deposits will impede the butterfly in the IAC from doing it's job; clean it and you're good to go. If it's broken, replace it...if it's dirty, clean it. If the car misfires while driving, it's not the IAC causing the problem. This works on some cars to diagnose MAF issues; unplug it. A lot of cars have a default tune they revert to when you unplug the MAF and if your car runs better with it unplugged, you can start to narrow things down a bit (not a spark or fuel delivery issue). Default tunes run a bit rich so keep in mind that a vacuum leak, which can cause your issues, can also be masked. Check the boot between the MAF and TB for visible cracks or tears. Squirt some of the leftover TB around the manifold, where the TB screws into the manifold, around booster hoses, etc. while the engine is running and listen to see if the idle changes. If it does, there's your vacuum leak. A misfire can be created in lean/rich conditions such as an unmetered vacuum leak or a MAF that took a shit. You may also have an ignition coil getting a bit weak or arching; that'll cause a misfire and will cause carbon buildup upstream if left alone long enough. Last thing to check would be the PCV (crank-case purge valve) system. A faulty PCV system will not allow excess crank case gases to enter the induction system to be burned away. This usually rears its head at idle. |
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Mechanic here.
Whens the last time you had spark plugs done? If they are due replace them.(this is most likely your problem) keep in mind last time i replaced spark plugs on sante fe i had to remove upper intake manifold. If thats not the problem replace wires OR swap #2 coil or spark plug wire depending on setup for another and see if misfire moves to different cylinder. If thats not the problem you can swap injectors from one cylinder to another but this is a little more tricky. If misfire still doesnt move to another cylinder do compression/cylinder leakdown test. Also you most likely need a catalytic convertor but fix this first and catalyst code has a rare chance of going away |
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Quoted:
Get a couple cans of CRC MAF cleaner. Why a couple? It works awesome on pistols, especially polymer. The IAC valve is basically a 2nd throttle body that opens up a little bit when the car is at idle and the main TB is fully shut. Some throttle body cleaner shot into it is usually enough to blast the carbon out of it and get it running again. Unless it's an electrical issue, deposits will impede the butterfly in the IAC from doing it's job; clean it and you're good to go. If it's broken, replace it...if it's dirty, clean it. If the car misfires while driving, it's not the IAC causing the problem. This works on some cars to diagnose MAF issues; unplug it. A lot of cars have a default tune they revert to when you unplug the MAF and if your car runs better with it unplugged, you can start to narrow things down a bit (not a spark or fuel delivery issue). Default tunes run a bit rich so keep in mind that a vacuum leak, which can cause your issues, can also be masked. Check the boot between the MAF and TB for visible cracks or tears. Squirt some of the leftover TB around the manifold, where the TB screws into the manifold, around booster hoses, etc. while the engine is running and listen to see if the idle changes. If it does, there's your vacuum leak. A misfire can be created in lean/rich conditions such as an unmetered vacuum leak or a MAF that took a shit. You may also have an ignition coil getting a bit weak or arching; that'll cause a misfire and will cause carbon buildup upstream if left alone long enough. Last thing to check would be the PCV (crank-case purge valve) system. A faulty PCV system will not allow excess crank case gases to enter the induction system to be burned away. This usually rears its head at idle. Quoted:
Quoted:
thank you both. I wanted to get oil change stuff for my car tomorrow so I will pick up MAF cleaner while I am there. Get a couple cans of CRC MAF cleaner. Why a couple? It works awesome on pistols, especially polymer. The IAC valve is basically a 2nd throttle body that opens up a little bit when the car is at idle and the main TB is fully shut. Some throttle body cleaner shot into it is usually enough to blast the carbon out of it and get it running again. Unless it's an electrical issue, deposits will impede the butterfly in the IAC from doing it's job; clean it and you're good to go. If it's broken, replace it...if it's dirty, clean it. If the car misfires while driving, it's not the IAC causing the problem. This works on some cars to diagnose MAF issues; unplug it. A lot of cars have a default tune they revert to when you unplug the MAF and if your car runs better with it unplugged, you can start to narrow things down a bit (not a spark or fuel delivery issue). Default tunes run a bit rich so keep in mind that a vacuum leak, which can cause your issues, can also be masked. Check the boot between the MAF and TB for visible cracks or tears. Squirt some of the leftover TB around the manifold, where the TB screws into the manifold, around booster hoses, etc. while the engine is running and listen to see if the idle changes. If it does, there's your vacuum leak. A misfire can be created in lean/rich conditions such as an unmetered vacuum leak or a MAF that took a shit. You may also have an ignition coil getting a bit weak or arching; that'll cause a misfire and will cause carbon buildup upstream if left alone long enough. Last thing to check would be the PCV (crank-case purge valve) system. A faulty PCV system will not allow excess crank case gases to enter the induction system to be burned away. This usually rears its head at idle. I like to use a propane torch or propane bottle with a hose hooked up to it. Without lighting the flame squirt the propane around the vacuum lines and if theres a leak it will get sucked in. Not as messy or as big of a fire risk as the old starter fluid on the engine routine. |
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Quoted:
I like to use a propane torch or propane bottle with a hose hooked up to it. Without lighting the flame squirt the propane around the vacuum lines and if theres a leak it will get sucked in. Not as messy or as big of a fire risk as the old starter fluid on the engine routine. Quoted:
Quoted:
Quoted:
thank you both. I wanted to get oil change stuff for my car tomorrow so I will pick up MAF cleaner while I am there. Get a couple cans of CRC MAF cleaner. Why a couple? It works awesome on pistols, especially polymer. The IAC valve is basically a 2nd throttle body that opens up a little bit when the car is at idle and the main TB is fully shut. Some throttle body cleaner shot into it is usually enough to blast the carbon out of it and get it running again. Unless it's an electrical issue, deposits will impede the butterfly in the IAC from doing it's job; clean it and you're good to go. If it's broken, replace it...if it's dirty, clean it. If the car misfires while driving, it's not the IAC causing the problem. This works on some cars to diagnose MAF issues; unplug it. A lot of cars have a default tune they revert to when you unplug the MAF and if your car runs better with it unplugged, you can start to narrow things down a bit (not a spark or fuel delivery issue). Default tunes run a bit rich so keep in mind that a vacuum leak, which can cause your issues, can also be masked. Check the boot between the MAF and TB for visible cracks or tears. Squirt some of the leftover TB around the manifold, where the TB screws into the manifold, around booster hoses, etc. while the engine is running and listen to see if the idle changes. If it does, there's your vacuum leak. A misfire can be created in lean/rich conditions such as an unmetered vacuum leak or a MAF that took a shit. You may also have an ignition coil getting a bit weak or arching; that'll cause a misfire and will cause carbon buildup upstream if left alone long enough. Last thing to check would be the PCV (crank-case purge valve) system. A faulty PCV system will not allow excess crank case gases to enter the induction system to be burned away. This usually rears its head at idle. I like to use a propane torch or propane bottle with a hose hooked up to it. Without lighting the flame squirt the propane around the vacuum lines and if theres a leak it will get sucked in. Not as messy or as big of a fire risk as the old starter fluid on the engine routine. I've always used carb cleaner since it will change the tone of the idle when there is a leak. I think Scotty Kilmer on youtube also had a trick to use Cigar smoke to pin point the leak exactly. |
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Oddly on my drive in this morning, the check engine light went out and the car seems to be running normally.
due to getting home late and weather, the first time I can work on this will be Sat. afternoon. I still plan on cleaning the MAF and IAC. We will see were it goes from there. |