My 94 started up the past several days, but after about 5 minutes driving between 30-50mph, it started bucking back and forth (kind of slamming the trans back and forth in the same gear), as it lost power and ultimately died in about 10 minutes. Same problem and reaction for the past 3 days. Starts up right away but then loses power and bucks and dies.

Read the codes today and it came up with Code 28 (above-mentioned O2 sensor in title) and Code 35 which LEXLS says is the HAC signal sensor (and then read an article that said it was a sensor in the ECU that apparently reads barometric pressure....if so I guess I would need a new ECU?).

1.) Could the dead upstream right bank O2 Sensor create the above bucking, loss of power and dying after 10 minutes?

2.) Also, does any one have any information or knowledge of the Code 35 HAC signal sensor and what it would do related to barometric pressure and or be causing a problem with my AFM?

Thanks for your feedback and help, T Cobb