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2005 Spectra LX
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Discussion Starter #1
Hi, I just bought a used 2005 Kia Spectra LX with less than 100k KM on it and it is getting terrible fuel economy. I'm getting about 350km off a tank of gas. I figured the first thing I would try replacing is the spark plugs because i know they are due at 96k and i doubt they've been done. I picked up two packs of Champion Platinum Power 3071 as per the Walmart parts guide but upon further research it appears that these may not be the proper plugs for this car. Does anyone have any advice on if these plugs are indeed the correct ones or not and/or what else i should look into for the fuel economy. Thanks
 

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2008 SpectraSX, 2014 Optima LX,2006 Jeep Liberty, Linux Mint Mate
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The originals were probably Champions (cross advertising agreement I read)..

NGKs and if they are not available Densos are the best choice.

Stay away from "special designed" plugs like those with multiple electrodes from Bosch. They WILL cause CELs (engine trouble codes).

The Spectra engine has been upgraded/re-designed from the original plans and Hyundai/KIA used NGK plugs during the design and testing. They just run better with them. Densos are also a prefered design. Check the gaps (.044")
I changed the Champions supplied with my wife's 07 Spec at 59k when the center electrode ceramic insulator cracked around and allowed it to fall down..effectively insulating the spark from the gas vapors...Had a P0303 code (mis-fire cylinder 3).
I put NGK platinums in and her mileage went up.
Dave
 

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2005 Spectra LX
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14 Posts
Discussion Starter #3 (Edited)
Thanks for the quick reply, DavesSpectra. I have another problem now after changing the sparkplugs. I took your advice on the NGKs and brought the Champions back to Walmart. The NGKs were from Canadian Tire with the number BKR5EGP. I gapped them to 0.044" and changed them out. Took the car out on the road for a test afterwards and it seemed to be running the same as before until i hit about 75-80km and it started shaking badly. I kept going and got it up to 110-120km and the shaking seemed to even out slightly after 20minutes or so. But my question is, is this normal after changing out the sparkplugs? Is it just the ECU relearning? Thanks again

Also, there is no CEL
 

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2006 Spectra5
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i just replaced sparks and wire set and it worked great and runs much smoother. NGK iridiums is what i went with. But as to your shaking problem i had the same. between 60-70mph it would shake pretty bad and when i went above it would pretty much go away. i got a new set of Kelly GT tires and it went away completely(maybe SLIGHT steering wheel rattle but thats it) So id say check your tread wear and start from there, it is probably the right answer to your problem.
 

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2005 Spectra LX
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Discussion Starter #5
i just replaced sparks and wire set and it worked great and runs much smoother. NGK iridiums is what i went with. But as to your shaking problem i had the same. between 60-70mph it would shake pretty bad and when i went above it would pretty much go away. i got a new set of Kelly GT tires and it went away completely(maybe SLIGHT steering wheel rattle but thats it) So id say check your tread wear and start from there, it is probably the right answer to your problem.
It definitely isn't the tires, or at least i hope not. They're new with less than 900 km on them. I think it might have been snow or ice buildup from the storm we had as it seems to have gone away on it's own. Thanks for the help
 

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2005 Spectra LX
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Discussion Starter #6
I have more conflicting part numbers if someone would be kind enough to clear them up for me. I'm going to change the upper O2 sensor even though the CEL isn't on yet. Canadiantire says i need NGK 24304, whereas NAPA says i need NGK 24353, and the NGK site doesn't have a part number. I looked through the KIA tech website but never found anything. Either i'm not looking in the right place or the part number isn't there?
 
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