Well, there are a few ways to determine if there is a performance calibration, which is what we call reprogramming the PCM.
First, a tech should read the data in the system during a drive cycle, which will tell him fuel trim readings, spark advance, fuel injector on time, and other things.
The next thing a tech will do, is to reflash and confirm that a GM program is in there. Only a GM scan tool, and computer terminal can do this.
If you like, I can research your VIN and let you know the correct calibration number, and anyone with a Tech 2 can check the number to confirm.
I think that this would be your first course of action, as it is the least painful, and will tell you if you need a PCM update.
Let us know if we can assist further, c4c5
As usual, you are a valuable asset on this forum. The VIN is 1G1YY22GXW5101892. Isn't this recalibration simply a way to "trick" the fuel injectors to spray more gas into the cylinders? I ask because my gas mileage is around 19.7 per gallon and I mostly drive on the highway. Albeit, I take off fast to get around the 1 to 4 gate, but still my mileage is not as great as other C5s.
Anyway, because this is such a bad time to try to sell used Vettes, and since my new car won't be delivered until the end of April, I decided to invest a few bucks into my car to make it more attractive for the next owner.
In doing so, I am finding out lots of details about this car. I suspected this car was used for racing for several reasons. The F45 option, 6-Speed and lowered suspension would indicate a car that someone wasn't going to drive to church and back.
In addition, I had to have frame around the front seat replaced because it was pulled away from the leather. It looked like a centrifugal force issue, in other words, I think this person cornered at high rate of speed!
Needless to say, I have had a ball in this car. I also don't drive it to church, but definitely push it to it's limits. It's amazing what these cars can do!
Thanks for running the VIN, and I look forward to seeing the results.
In your opinion, is a recalibration a good selling point?
Your calibration number should be 9355159.
Your specialist will be able to access the ID number to confirm this.
As for the program adding value, with those mileage figures, I would say no, only because I see autos with 27 highway at 70 mph.
So, what happens is up to you, however, I would kill the performance program, and get it back to GM calibrations.
I also have a used 1998 C5 but feel mine is all original since it never had the recalls done on it. I was wondering if it might be wise to have the PCM checked to see if it's software is up to date. Is it possible that GM has revised the PCMs software for a 98?