How to detect a downloader?

[BHolm]

I just bought this truck used a few days ago. It was run pretty hard by the PO. It appears stock except for the straight pipe. What tipped me off was the overhead mpg readings. It reads about 5 mpg high. Now admittedly I just checked after running a half a tank through but I expected it to be much closer. Hoping by some miracle anyway, since it was reading 25 mpg! Actual hand calc was 19.



From reading the forums it seems like the programmers, whether installed or downloaded, seem to mess up the overhead by about that amount. I know the overhead isn't perfect but of the other trucks I have had, those were always within 1-1. 5 mpg. It also seems pretty quick, and lets out a little more smoke, though that could be my imagination.



So, since I haven't found a box installed anywhere, and there are no gauges installed, is there a way to find out if a program has been downloaded? Where should I look to find a box? I checked under the hood and under the dash and don't se anything. I bought it from a dealer so I am not sure if the PO is going to be easy to contact.

 

[d90boy]

Seems like I've read where the smarty is the only one that doesn't reset the key on counter. So if it had anything else, looking at the key count may reveal whether it had a programmer.

 

[AKaiser]

Seems like I've read where the smarty is the only one that doesn't reset the key on counter. So if it had anything else, looking at the key count may reveal whether it had a programmer.

The Smarty even shows you how many times the key has been turned.

 

[BHolm]

Is this going to be something that requires the factory scan tool?

 

[betterthanstock]

I just bought this truck used a few days ago. It was run pretty hard by the PO. It appears stock except for the straight pipe. What tipped me off was the overhead mpg readings. It reads about 5 mpg high. Now admittedly I just checked after running a half a tank through but I expected it to be much closer. Hoping by some miracle anyway, since it was reading 25 mpg! Actual hand calc was 19.



.

You could still have bigger injectors installed. Take it to a dyno, and measure your power.

 

[TFlory]

The overhead is simply not accurate. I wouldn't assume the PO used a dowloader just cuz it's incorrect...

Also, the bully dog doesn't reset key cycles either.

TIM

 

[AKaiser]

The overhead is simply not accurate. I wouldn't assume the PO used a dowloader just cuz it's incorrect...

Also, the bully dog doesn't reset key cycles either.

TIM

Amen. No two trucks read the same. They don't call it a lie-o-meter for no reason. Mine is usually 2 MPG high.

 

[scootergmc]

Mine is almost dead on. Although I havn't read anything on these forums with an indicated 6 mpg off. That seems a little excessive.

 

[Cal Brewin]

My truck is stock, and has always read about 3 mpg higher than hand calculated.

 

[Alan Reagan]

The overhead is simply not accurate. I wouldn't assume the PO used a dowloader just cuz it's incorrect...

Also, the bully dog doesn't reset key cycles either.

TIM

I agree. On my 05, the overhead was accurate at first but after 67K, it is now reading three to five over. Seems like the more I reset, the worse it gets. I don't a downloader is the only thing that causes this. I would like to find a way to really reset the thing so it is more accurate.

 

[Boondocker]

Maybe the PO or someone programmed it for the wrong tire size. That certainly would affect MPG calculations... because the speedo would be wrong. You might want to use a GPS or calibrated stretch of highway to check your speedo accuracy.

 

[BTighe]

my 06 was about 5% fast on the speedo.

 

[BHolm]

The tire size has already been adjusted for. This is my sixth third gen and it would be the first one that was that far off. I have had them all on cross country trips and verified that the overheads were within 1-1. 5 mpg. I have seen them lie on either side but never by 5-6 mpg, regardless of how many miles were on them.



My main concern is that I want to use a Quadzilla XZT, and I was hoping to get away with no gauges for a short time. If there is something else already installed though, and I inadvertantly stack it without gauges, I do not need to burn it down.



So it sounds like the only way to detect a downloaded program is with the scan tool.

 

[AKaiser]

Maybe the PO or someone programmed it for the wrong tire size. That certainly would affect MPG calculations... because the speedo would be wrong. You might want to use a GPS or calibrated stretch of highway to check your speedo accuracy.

I ran calibrated stretch of US 31 between Edinburgh and Franklin, IN, and there are inaccuracies in the "calibrated" road. I think the second sign on the northbound side was moved, or they screwed it up on install.

 

[AKaiser]

The tire size has already been adjusted for. This is my sixth third gen and it would be the first one that was that far off. I have had them all on cross country trips and verified that the overheads were within 1-1. 5 mpg. I have seen them lie on either side but never by 5-6 mpg, regardless of how many miles were on them.



My main concern is that I want to use a Quadzilla XZT, and I was hoping to get away with no gauges for a short time. If there is something else already installed though, and I inadvertantly stack it without gauges, I do not need to burn it down.



So it sounds like the only way to detect a downloaded program is with the scan tool.

Smartys have the stock parameters in them, so I think if you had a Smarty, you could reset your rig to stock with a Smarty, then go from there. Smartys rock, BTW, and are a good base to stack with.

 

[Cummins Cowboy]

My truck is stock, and has always read about 3 mpg higher than hand calculated.

ditto that, same stock and same after the smarty

 

[JThiessen]

Smartys have the stock parameters in them, so I think if you had a Smarty, you could reset your rig to stock with a Smarty, then go from there. Smartys rock, BTW, and are a good base to stack with.

He cant do that unless he's got the actual Smarty it was programmed with - assuming it was programmed with a Smarty. I highly doubt its got a program in it. My bet would be injectors if anything, and possibly a Roktec adjutable timing sensor.

 

[BHolm]

I would bet it isn't injectors either. I did a valve adjustment today and when I removed the cover, one of the back bolts had a valve lash spec sticker that was partially covering the bolt. I would bet I am the first to have pulled it off.



Maybe it just is a wildly optomistic overhead. It is possible that it is about 3 mpg off and my half tank hand calc is just too small a sample to be accurate. I would guess that most guys, especially if towing heavy, which this guy did, would have gauges. There is no evidence of an egt probe anywhere, nor does it look like any of the intake bolts have been removed recently for a boost fitting.