Are spark plugs all the same?

[Dave Thomas]

Use oem plugs from a reputable supplier not from the internet. You would be better off having it diagnosed correctly instead of hoping it will fix your problem. Reading codes is not a diagnosis and a code scan is not a parts list.

 

[fmyth]

I just read your first post again. You stated that the car does not idle at the same rpm and you have taken it to a mechanic. Did the mechanic pull any codes? Although the plugs are due for replacement I wouldn't assume they are the cause of your idle issue. Problems with idle can be caused by a dirty throttle body, dirty or failing MAF sensor, dirty or failing throttle position sensor (TPS), or a failing crankshaft position sensor.

If it were my car I'd take it to the local parts store and have them use their scanner to connect to the OBD-II port to check see if there are any diagnostic trouble codes. If there are codes write them down and google the code to find common causes, symptoms, and potential solutions. If there are no codes I'd replace the spark plugs with OEM's, put a can of injector cleaner in the gas tank, clean the MAF and throttle body. You can find youtube videos to show you how.

 

[xziang]

2nd with what some others have said go with a similar oem plug. This is also a product I would buy from a dealership or NApa or well known auto parts store. Avoid amazon and ebay due to fakes, not worth the risk to save a couple bucks.

 

[Yoder]

I only use what the vehicle manufacturer recommends. Nothing else. I used to just buy middle of the road priced plugs until I had my car go into limp mode 50 miles from my house after changing my plugs one time.

 

[49ereric]

Get a 1 step colder plug if possible and open the gap to max or 5 thousands over.
Research on your car should tell if the coils will handle a larger gap and how much.
I have done this on older ford focus’s and mpg went up. Larger vehicle results will vary.

 

[fmyth]

Get a 1 step colder plug if possible and open the gap to max or 5 thousands over.
Research on your car should tell if the coils will handle a larger gap and how much.
I have done this on older ford focus’s and mpg went up. Larger vehicle results will vary.

Putting a colder spark plug in a stock car generally does nothing positive and can cause problems like fouling, misfires, and reduced performance because it won't get hot enough to self-clean. Trying to regap OEM Iridium plugs for this car will cause them to fail prematurely.

 

[49ereric]

Putting a colder spark plug in a stock car generally does nothing positive and can cause problems like fouling, misfires, and reduced performance because it won't get hot enough to self-clean. Trying to regap OEM Iridium plugs for this car will cause them to fail prematurely.

Disagree completely.
Modern cars run lean so fouling is a non issue. Over a 100,000 miles on a step colder DP auto lite plug in 3 different focuses. 2-3 more MPG but I drive for gas mileage.
copper plugs will give you more but will the stock coils handle it? Plus who wants to change plugs every 6-7k.

 

[BigNate]

At that milage a full tuneup is justified. With some cars a timing belt is also due, and a loose belt can cause idle issues somewhat.
Fmyth nailed it though a MAF/MAP sensor that's dirty combined with a tired O2 sensor or sensors all play a part.