It has been an issue that pops up from time-to-time that a vehicle experiences ZERO change in mileage, no matter what is done.
And I mean no matter WHAT! They report (both PRE- and POST-Groove!) that their mileage doesn't change whatsoever. Flatlands or mountains, 35 or 135 MPG. Octane boost or no. No change.
There can be only one way this could happen, and that lies in the BRAIN that controls the fuel delivery, or the ECU (Engine Control Unit).
Following a call with a client expressing this concern, I decided to try something different. I asked more QUESTIONS. This client is unique, as he began to tell me about all the work he had done on his ride. EGR replaced. Intake manifold replaced. O2 and Catalytic converter replaced. ALL BEFORE THE GROOVE!
What did he get? ABSOLUTELY NO CHANGE. (well, he HAS recorded as much as a 0.68 MPG variance.)
So, he began to speak about emissions. It turns out that this truck has California Emissions (ALERT #1). Second, it was released as a "LEV" or Low-Emissions Vehicle. (ALERT #2)
We are now embarking on an experiment. I offered to split the cost on a replacement ECU for his truck. On this particular model, there were over FIFTY DIFFERENT ECU's USED! So, I scanned, selected one from the NON-LEV crowd with the configuration most closely matching his application, and placed the order. (This was yesterday.)
He did a check unbeknownst to me, and when I called him back told me "If I replace this ECU, it MUST be programmed by the dealership, and that's almost $200!!!"
I advised him NOT to do that. We're approaching this from a country-boy perspective. We're going to put it in, and go through the reprogramming Gadgetman Style. Then, and ONLY then, if it doesn't respond, we'll take a look at that option.
I will try to keep you all updated on the progress, but until then, I want you ALL to post the vehicles you have that mirror this report so we can work together as a team to solve this problem.
It is so frustrating to have this happen, and when it DOES, we want to be able to solve for this, because it is harming our clients, ourSELVES, AND the PLANET!
Ron