1998 Ford F-150 truck year and spark plugs problem.

BRETT61390

MEMBER
1998 FORD F-150
V8
4WD
AUTOMATIC
69,200 MILES

Hi I'm new here and don't know too much in terms of trucks and had a question. I bought a, what the Ford dealer said, was a used 1999 ford f150 5.4 V8 4WD super cab. I just noticed putting new speakers in the other day that the sticker on the rear swing door that the manufacturing date sticker said 11/98. That worries me because last month I replaced the spark plugs (which was a pain and took me about an hour; having to take the fuel rails off and everything to get to them) and told the guy at the auto zone store that it was a 1999 and gave him the rest of the specs. He gave me the plugs that matched that vehicle. Im wondering how bad it is that I did that or if the 98 and 99 use the same plugs or if its not a big deal. I noticed that the plugs I put in (bosch platinum +4's) had a lot more threads than the ones I pulled out (motorcraft platinums) However the trucks been running fine with no misfires or rough ideling or anything. Nothing but smooth acceleration and no hesitation. Running better than the ones before. Any recommendations?
thanks

2 Replies

OBXAUTOMEDIC

MECHANIC
3,711 POSTS

Hello,

No worries, The date of manufacture reads 11/98 would be concidered a 99. The cut off dates for whether it would be a 98 or 99 would be Aug or Sept but anything after Sept would be concidered a 99. However, if it does still concern you you can always have the parts store look up the parts for both years and 99.9% of the time the parts will be the same.

.