Hey guys, I'm really hoping y'all can help me out. I have a 94 bonneville (vin L) that stutters and shakes when the torque converter locks up, and bogs out above 4,000 RPMS. I've given it a tune up, tested the coolant temp sensor, MAF, TPS, replaced the coil packs and module and no difference (although when I replaced the o2 it helped). I was thinking it was the crankshaft sensor but i know when that goes out, it goes out completly. The SES light is on, and if you disconnect the battery cables to reset the ECU, the SES comes on immedatly. I had the code checked once and i can't remember which code it was, but the tool and the book said it was an o2, sesor 1, bank 2, or somethin like that, it only has one o2 so i thought the book and the tool where giving me the wrong info since it'* an in-between year (OBD1-2, i had the same problem on my '95 blazer, OBD2 conn. but you had to read it with and snap-on OBD1 scanner with a special plug that had "keys"). Anyway I've been stumped on this car for over a year now. If anyone has any clue PLEASE help me.

To accurately diagnose this, we really need the codes. Since it is the hybrid year, you'll need to have a shop scan it.

But, in the mean time....

What did your tune up involve? Plugs and wires? If so, what brand and how long ago did you replace them?

Have you ever changed the fuel filter? I suggest changing the fuel filter. If it'* clogged, the engine is starving for fuel. Also, check your fuel pressures at the fuel rail.

i'll get back to you on that.......

Welcome to the club. Like vital49 said, get the code(*) and we will be able to help alot better. Where are you from? Maybe there is a member nearby that is willing to scan or help with diagnosis.