I recently bought a used ecu because I was having problems with my egr and passing smog with my original ecu, the down side to this new or shall i say used ecu is my shift light is not working any more since I replaced the ecu, Is there a fix to this? and will the light not working effect my mpg?
The light only informs the driver as to the most efficient time to shift. It doesn't do anything to the engine or fuel injection, so if you're good, it won't make a difference. HOWEVER, the ecu's without the shift indicator light are California versions, which also don't have lean burn, and that will make a big difference on fuel economy, roughly 5mpg. The ecu you want is the P07 A00 or P07 A01. If yours says P07 L00 or P07 L01, you have the wrong one.
EDIT: I just noticed you're in CA, so I'm assuming you have a 49 state car?. Otherwise you shouldn't have had a shift light anyway.
Yes I am in Cali , my car does have the indicator light, my ecu is the P07 L00 curently in the car, but why would the egr only work with the Cali ecu I'm sure that I had the P07 A and i could not pass smog test with that ecu, the guy I bought it from had four, I tried them all the one bought was the only one that made the egr work, another one I tried worked the same as my original ecu, shift light worked & and vacuume to the egr at 3500 rpm. Whould the egr not working effect mpg?