97 Olds 88 LS (non-super 3800) sorry, this is long but dont want to skip something that might be important, thanks in advance
The car has been driving me nuts. I had a lean bank one code. I did have a vacuum leak between plastic upper plentum and the lower intake manifold. Installed new plentum. Still had a tiny leak that I could find with carb spray, sealed it and still got the lean bank one code even though I couldn't find any un-metered air leaks. Ran great however, should have quit there but wanted to get rid of lean code. Upon close look at O2 sensor, it looks like a generic 4 wire had been spliced in. The wires were not lined up according to color, ie- black to black, grey to grey, and 2 whites to whites. Figured this was a problem so I cut the wires, added connectors, and put the black to black, grey to grey, etc. Now it ran crappy with a lope at idle and got an o2 sensor "no activity" code but the lean code went away. swapped em back to mis-wired and ran better again, lean code returned, and o2 no activity code went away. Decided to replace o2 sensor. ran crappy and got "o2 sensor no activity" code again. Decided to mis-wire it again to at least make it idle good and must have mis wired it different/wrong because I heard a "pop" and saw an o2 wire glowing bright. shut er down. went back to old o2 sensor and now (after pop/glow) I have the TCC and evap codes. Specifically P0740 Torque converter clutch circuit open, P1655 evap purge solenoid control circuit, and evap vent solenoid control circuit.The torque converter solinoids are not getting a signal I guess because it has reverse but slipps in forward gears. Both the Torque converter code and the evap codes popped up after the ominous pop sound and burnt o2 wire incident.

I figured I had fried my PCM so I replaced it today and instantly got the same codes.

What did I blow/melt? Is there a common element I can check for trans (torque converter) AND the evap system? I can't find any blown fuses, runs fine (but won't go with no torque converter clutch).

Did I turn my car into a parts car? I sure hope not, can't afford that.

Did you check all your fuses? I believe there is a fuse panel under your glove box. Check there.

i dont know about your tcc but the evap and o2 are on the same circuit

Like mentioned, I'd check all fuses.

An O2 sensor is not going to cause a lean bank code tyically. It'* the item that reads the issue, the pcm then reports it. Most likely your EGR to LIM tube is cracked. Maybe your evap is hooked up backwards (because in 97 it'* possible, I did it).

Bill, I'm going crazy checking fuses, driver and pass footwell, big ones on firewall. I'll go back. Sure seems seems like it should be a fuse. Gotta find this issue first because I have no car without power to TCC. I'll pull upper again after to check/ replace egr tube in lower.
JW, thanks for the diagram. Looks like it says fuse 5 for evap,o2.
Any other hidden fuses on this thing anywhere?

This is a 4t65 transmission right? You can check for voltage on pin E on the plug. If you look in the plug there is a row of pins in the center, I believe pin E is the only one on that row. Check for voltage with key on. If no voltage, then you have a blown fuse or broken wire. They seem to move that fuse around and give it stupid names, look for something along the lines of misc engine/cruise control

im sorry i just realized i posted the wrong year. on the 97 the trans and those other things come off that fuse 5

ta-da! thanks for holding my hand guys.
#5 fuse(pass footwell) was blown.
I had checked it with my fuse checker and the light lit up. Must have been a closed circuit the long way around even with the fuse blown. Pulled it and yep. TCC and evap codes gone.

Bill, that egr tube that comes up from LIM, if it has a crack, would that be enough for a really rough idle? Lopes and wants to stall.

Still getting a "no activity detected" O2 sensor code. It should have power because the STUPID "misc engine controls" (#5 fuse) has the heated o2 sensors and the evap solenoids on it. Cant figure out why I'm getting the o2 code. I suspect (?) the o2 sensor is changing the mixture and making it idle funny?

Glad you found it, that fuse is what power pin E.

Yes, a cracked EGR tube will make the engine lop real bad, kind of sound like it has a cam. and finding the crack is a pain because you need to take the tube off and look.

oh boy, fun. Thanks Dan, I'm tired of pulling the plentum

Never dealt with the inside egr tube before.
The flexable tube from the egr valve to the LIM bolts on to the lim just below the throtle body. Am I right in thinking that the tube that goes up from the lim into the plentum is a seperate (short) tube? this must be the one that can crack otherwise I would not have to remove plentum to get at it. Is it repairable? Dealer only item? Probably have to wait for order time because of year.

Is it removed with a gentle pliers action?