I have the 5.4 in a 98. How do I know what hp model I have?? I was told mid year 98 they changed to the 260.. Any vin numbers or visible evidence?? I did a search and found lots of articles, but no definte answers..

 

umm check the MAF if its black plastic is a PI head model if its non PI the MAF will be aluminum. look for the vin number on the heads to see if it says PI on there

 

I believe that the change was made mid '99 model year. They went with new heads. I remember seeing someone post that you can tell if you have the 260hp version if you see PI stamped on the head. 235ph=pre PI (power improved) 260=Power improved.

I could be wrong, but I'm pretty sure this is how I've seen it said.

 

I believe wittom is correct. I believe they changed the body style a bit different as well when they changed the motor too. Changed the bumper up a bit different and the door trim. My 99 is the later model.

 

They also changed the bumper, the grill shell and grill itself, and the instrument cluster was changed as well. And the PI heads also were put on in the 99' model year.

 

Sorry, I just found this site. I don't know what a MAF is??

 

MAF is the Mass Air Flow sensor, its located inside your throttle body. Pull your air filter out, and look down into your throttle body towards your motor, youll see a little round thing with two little bitty bitty tiny wires--thats your MAF.

 

I believe the power improved 5.4L came out in 2002 and increased to 300 hp in 2004 with 3 valve 5.4l. I've retired from the plant that manufactured the 5.4l. There were two plants that manufactured the engine. I believ one was Romeo Engine and the other Windsor Engine plant. I can find out for sure. in a couple days.

 

quote- "I believe the power improved 5.4L came out in 2002"

No, it didn't.

 

YOU'RE RIGHT