Tuned '95 ECU in a '98... [Archive] - SaabCentral Forums

: Tuned '95 ECU in a '98...

19th October 2009, 12:54 AM
Would this work? I'm putting on the TD04 next weekend and have a JZW tune from a '95 to put in with it. The only difference I can think of is OBD I vs. OBD II...does that mean all i have to do is unhook my second O2 sensor and block that bung? Or is there more to this that I am naively missing?

19th October 2009, 09:48 AM
If you run that way unhook and plug the engine side of the tank purge hosing. The old ecu will hold the tank purge solenoid open allowing boost to pressurize the fuel tank. The pump cover will crack.

mike saunders
19th October 2009, 10:06 AM
^^^^ +1

fiveiron, you should always try to match ECUs within the same year, if not within the same general family (OBD I, OBD II), and same transmission type.

The EVAP system is pretty finicky if not accounted for, and you'll either pressurize the tank as Nick said, or you'll run the risk of a tank vacuum that will make you run lean.

Sucks either way.

19th October 2009, 11:09 AM
Yeah I didn't know the model year difference until i bought the ecu. So it would be best if I get it retuned? Or do I need a whole different ecu altogether? Thanks for the help.

What do I do with the hosing I unplug? Should I plug that hose too then?

John Z Williams
19th October 2009, 03:13 PM
Send it to me and I will change the base file for you.