It still didn't work? Bum deal! I just had the exact same thing happen to me (chug at low rpms) and it ended up being my plugs. However, my dummy light did come on - my 2nd cyl misfired - the mechanic at the corner shop told me that a misfire can be three things. 1) bad plugs/wires 2) clogged fuel injector 3) intake manifold gasket gone bad.

so....maybe look to see if the fuel injector has ever been cleaned (the guys here can advise you better on this than me - I have my son do it at Valvoline where he works) ....and keep a check on your coolant. I've heard nasty rumors about the DexCool coolant eating up the gaskets....

I had it back at the tranny last weekend and took one of the techs out for a drive while he watched the scan tool. Only happened once, but it happened. The tech said that it did look as though the torque converter clutch was slipping. Apparently there are a number of things that can cause this. They offered to do a free diagnostic tear down for me since I'm looking at replacing the worn/bad parts with performance parts and will need to order them. So I need to schedule that and get a rental car for the day...maybe Friday or Monday. I'll let you all know what comes of it.

rusty coil..............happened to me

care to elaborate on that? Which coil are you talking about?

I believe he may be talking about the coil packs. Some of them can have a rusting/corrosion problem on the tips where the plugs attached. I'd think you would have noticed this when you replaced your wires however. Mine had it, my friends 2000 SSEi had it, and my son'* 99 Grand Prix did also.

It only takes a second to check, so I'll take a look at this while I'm on lunch

you might want to do some checking, i just sold a car to a customer a 98 lesabre and he experienced the same thing, if you drove the car ever so carefully and slightly pressed the accelerator over 40 mph you could see the tach move from 4-700 rpm,and feel the shuddering sometimes a little more aggressive than others. turns out there was a update in the valve body to cure this cost me 450 to repair, tranny shop wanted 900+ ,

ive been managing a family run uded car dealership for 15 years, and the bonneville is the best around, anyway i just registered here because after 10 years of leasing i finally bought a vehicle , only one choice 2001 bonneville ssei with 42k

check with your local mechanic if he has alldata he can look for the upadate, my bonneville just started to do the same thing and now my milegae has dropped to 18,
gonna have to get it done

my 2000 SE is doing the same thing only with the added problem of rough shifting in and out of third jolting the car hard sometimes and not so hard other times... about this update on the valve body... can you elaborate?

My baby has 122K miles on it and my gas mileage is at about 17 - 18 mpg.

I second that. I had the same exact problem with my 93 bonne, and it was just wires.

I am running into the same issue that everyone else seems to be describing. I had the torque converter clutch issue during the warranty period and they tried to fix it, but really only made it a little better (I was told that was all they could do after having it in the shop 4 times). I learned to live with it since it was only a light slipping, and pressing the accelerator just a little harder resolved it, but now it has gotten worse and there is a bit of a hard shift in and out of all the gears, and a slight chugging at times now too. We flushed the tranny (the fluid was awful, and it had been flushed just last year), and tried a better gas, and it cleared up the gear change issue, but the chugging and 40-50mph issue is still there. I'm thinking at this point that since the car has 89,000 miles on it and it has original plugs and wires, that those need to be done and may resolve it. I will also clean the throttle body and the fuel injectors, and see if that helps. I am glad this thread was here since it fits my current issues perfectly.