I just bought a 99 dually.

How can I find out if its got a chip in it or not?

It seems fairly good for power but its only got 30,000 miles on it so it should run OK.

Its got a sticker on the back that says "Power Force Computer Chip".

Im undecided driving it , sometimes it feels like it might but sometimes it feels stock.

Anyone know how I can tell?

 

Wow. That looks like a heck of a paint job. To see if there is a chip, pull the key out of the ignition and unbolt the PCM to see if a chip has been plugged in. You could probably just inspect the PCM visually to see if there is a chip installed. Typically there's a section of plastic cut out of the back of the PCM case where the chip goes. Sometimes with a strip of tape across it holding the chip in place.

If it's a programmer installed, you could always go out and drive it hard for a bit and then get the truck scanned to look for the tell tale P0603 and P1211 codes to show up.

 

And the PCM is where?

I was thining the programable type?
Like the Edge in my 02.

 

the pcm is on the drivers side kick panel. to get it out you have to find the connector in the engine compartment under the brake booster take loose the 10mm nut and pull the harness off then you have to get up under the dash and remove a couple more bolts in the black plastic cover and the pcm will slide right out