When I got my car, the guy said he upgraded the computer. How can I find out for sure??

 

Open the ECM. Look at the MemCal. Inside you should see a large PROM with a label. If the date code is newer than the manufacture date of the vehicle, it isn't the original. It may not be an "upgrade", but your original PROM should have a date code older than the assembly date of the car. The month/year of assembly is on a label in the driver's door jamb.

 

Just like he said

 

How exactly do I open the ECM??

 

sounds like he put a new chip in there.
layman term "i upgraded my computer"
biker

 

I am not a very easy person to convince. I need proof. So, who do I check the ECM?? Thanks for your help!!