1996 gts.....1999 ecu?

[dodgestang]

So uncovered a new secret with my 96 GTS this week.

For some reason it has a 99 ECU in it.
The 99 ECU spits out a vin that isn't my car Vin (for obvious reasons) but shows very similar mileage as what is on the car.
We had the pan off the can and it definitely has a fully forged bottom edge so I don't believe there was a motor swap done on the car....just appears like an ECU swap.

From a performance stand point it has stock rockers in the heads (because we pulled a valve cover we could verify that) but it has after market accufab throttle bodies and exhaust work. Is swapping in a later model ECU something does as part of a mild performance upgrade?

[99RT10]

No, more than likely the original PCM failed and was replaced. There is no performance gain by using a 1999 PCM over 1996.

[dodgestang]

it must have happened realllll early it its life then (or it sat without driving a LONG time....or they lucked out with the replacement....there is only 500 miles difference between the odometer and the ECU

[Timnineside]

So uncovered a new secret with my 96 GTS this week.

For some reason it has a 99 ECU in it.
The 99 ECU spits out a vin that isn't my car Vin (for obvious reasons) but shows very similar mileage as what is on the car.
We had the pan off the can and it definitely has a fully forged bottom edge so I don't believe there was a motor swap done on the car....just appears like an ECU swap.

From a performance stand point it has stock rockers in the heads (because we pulled a valve cover we could verify that) but it has after market accufab throttle bodies and exhaust work. Is swapping in a later model ECU something does as part of a mild performance upgrade?

Didn't the 99's have a fully forged bottom end still? I thought they quit in 2000.

[dodgestang]

Didn't the 99's have a fully forged bottom end still? I thought they quit in 2000.

Hmm....internet is looking that way....for some reason I had it in my head 96 and 97 had forged and that the 96 had the 'more muscle car sounding cam'

[Tom Sessions]

The miles in the PCM can be changed with the DRB3 scan tool. It is not like the VIN# which you can not change. So don't put a lot of faith in what the PCM miles are.

[dodgestang]

Lie to me man.....make me feel better ;)

[slitherv10]

Are you sure it is not a performance ecu? Some did upgrade he pcm's to the performance ones and some are from 99. I know mine is in my 96..it is a performance pcm which are rare to find today.

[dodgestang]

I know very little about the car so everything is an archeology dig.

The only thing 'I know' about the ECU at this point is the Viper Tech at the dealer told me "Its a 99 ECU and has this VIN number in it and shows this many miles"

That's it. So I posting grasping at straws wondering if maybe it was some type of performance tweak from 'back in the day' since the car only has 18500 on the clock when I bought it....

[Viper Specialty]

Nope, as Tom pointed out, the programming in a 99 ECU is very similar to 96. No real gain. That said, it never a good idea to have someone elses VIN in your ECU, either for inspection or general use long term. VIN mis-match can cause fault codes, as well as issues with OBD-2 inspections.

[GTS Dean]

Need a new 96 JTEC? Shoot me a PM

[dodgestang]

Need a new 96 JTEC? Shoot me a PM

In all honesty....I'm not worried about.

I've had the car for 8 months, put 4k miles on it, and aside from the timing cover gasket, ac o rings, and battery drain (all of where where mechanical issues that have been fixed) haven't really had any issues. I had no issues with the title from MA to MD, nor with registration/inspection.....all of which is good for 2 years.....which means the next time I have to renew it will get classic car tags and doesn't even need an inspection then.

I have made a note in my hard copy file about the mis-match and the possible issues...so I will keep an eye on it.

[Dan Cragin]

A 1996 with a 1999 ECU should turn on the check engine light for Leak Detection Pump fault, unless its been flashed to remove that.

[dodgestang]

No CELs in the car.

But more good info.