Mechanics

LX USED THE WRONG SPARK PLUG

2000 Ford Focus • 97,000 miles

A few days ago, I replaced the spark plug on my Ford Focus 2000 LX in a hurry. I accidentally used the wrong spark plug - I used a Motorcraft SP 478 instead of the SP 504. However, the descriptions on these two spark plug are identical. Would using the wrong plug be causing my engine to misfire?
Avatar
JessicaLauren
March 19, 2012.




It could. What about the specs on the 2 plugs? Heat range, etc.

Rivermikerat
Mar 19, 2012.
Yes, Big Time
AD

Tiny
Rasmataz
Mar 19, 2012.
Yes, if spark plugs specifications are not what is recommended, it can cause misfirings as the gapping and heat range could be different.

KHLow2008
Mar 19, 2012.

AD