EGR, vacuum line(s), COP, or ??

[1997SCEBFEX]

Trans serviced regularly as per my above post.

Thinking DPFE as it was from one of the retail auto parts chains and has been nearly 4 years on that.

Have ruled out unmetered air getting in & chasing gremlins now.
Thanks for your replies!

 

[1997SCEBFEX]

Vacuum restored after installing new Vortech [standard] bypass valve.

 

[1997SCEBFEX]

Update:

I changed the EGR, DPFE, and green vacuum line to no avail Saturday.

Blue Oval says they no longer make this trans, but have an update to it and the labor is 1/2 the price of the trans; rough $3.6K for the works including a 3 year/36K warranty.

After having the motor done last year, perhaps on borrowed time on this trans since I'm pushing more overall HP? The torque converter was replaced once when new under warranty.

 

[1997SCEBFEX]

It finally set a DTC and it was P0122, throttle position sensor. Changed it yesterday, seems to work fine at speeds, but idles a bit high, 1200 rpms. Guess it will settle out. Any experiences here?