I have a 2000 Bonneville SSEI and It starts great runs great. However going down highway when you give it gas like to go uphill or to pass whatever...It just seems to have no power whatsoever It also bucks and jumps when doing that. I test it seeral times and it seems to be fine when in park just does it when driving..even taking off and getting into the gas a little it does it. Any and all help on this matter will be great!

Hm sounds like a TC issue how is your trans fluid?

Transmission fluid looks really good I have checked it. I was wondering if it might be a TC issue but not sure what.

Any SES lights?

The check engine light also will come on while it is "bucking" the light flashes and then goes off. If that is any help.

If it flashes that usually means a misfire..Very plausable

Hmmm I guess I am confused as to why it doesnt do it in park. I can sit in the driveway in park and it runs fine. When the light flashes like that does it still leave a code on computer if I was to have it scanned?

It may be stored..I would start yes by having it scanned and if nothing is there we can go from there

ok. I have a buddy that has an OBDII scanner I will see if I can get him to scan it tomorrow sometime.

Alright Be sure to let us know what ya come up with!