OK so i searched number threads on here and all the info was either old or not answered. Is it possible to convert a 05 silverado to run e85 on the stock PCM? If so, what would be needed? I have searched through information pertaining to the flex fuel 5.3 tahoes and such(03 models) and have determined that the primary differences were the flex fuel sensor, injectors and fule pump, along with the o3 pcm OS. Other than that, there isnt a other differences is their?

 

What are your goals? Actual flexible fuel capability or just running a fixed ethanol concentration? Things are much simpler if you stick to one type of fuel.

 

flex fuel capabilities...like the 2003 tahoes have

 

Your 05 PCM should have all the capability to do it, yes.

 

There were 05 L59 Silverados so there is no need to use a 03 calibration. O3s used a return style fuel system and 05s were returnless just like a non FF truck. Just add the FF sensor, wiring, and injectors and flash the PCM with a 05 L59 calibration. You could even put your VIN in the calibration to satisfy the VATS.

 

Thats why i was asking, the pcm has the os in it for e85, so why did those vehicles never came with it from the factory amazes me. I cant tell if my fuel lines are SS or not though... anyone know if they are?

 

@2zls1

The l59 was swapped for and lq9

 

Your posts are confusing. The OS for a 05 LM7 and L59 are the same but the calibrations are different,

 

Because calibrating seamlessly between two different fuels is more difficult than calibrating for one fuel. If every vehicle that could run ethanol did, customer complaints would inevitably be higher. Historically, domestic manufacturers have only sold enough flex fuel capable vehicles to meet requirements to receive EPA emissions credits.

 

the stock pcm that came with the lq9 has the provisions for flex fuel...(although it never came with flex fuel) which is being swapped in an 05 silverado

the silverado never had flex fuel, but the os from the original pcm had the provisions for it also..

i was wondering about if i just added the sensor, pump and injectors, would that be all i needed and how come ones done it.

sorry for the confusion