It seems that the only connection between the symptoms and the O2 sensor was the fact that it was occurring after the car warmed up.

BTW, you said that you had replaced that sensor just 2 weeks earlier. What brand was it (I know you said crappy $15 sensor)? Did you replace it with an AC Delco this time?

i replacted it 2 weeks before the problem started happening. the brand was Standard. this time its a bosch i know its crap but autozone napa carquest and the other store dont carry anything other than bosch so i had to use it. i looked over the wire on the old o2 sensor and it had a little slice in it. my guess is from when my i changed the spark plugs 2 weeks after and the problem started happening i must have hit the o2 sensor wire with the ratchet.

Oh. Well good luck with that Bosch sensor. As you know, many on here have had bad experiences with them on the Bonneville.

If you do end up having to replace it again, there are now a couple know good sources for the AC Delco sensor that will ship more rapidly, if past experiences are any indication.

hey lash what are the sources for the ac delco. the problem came back again today with the bosch sensor.

Hold on, be right back....<runs off to find thread with sources listed>...

OK...<out of breath>...back.

www.gmpartsdirect.com

You might consider reading this thread too. It has the above info, plus a good discussion on O2 sensors in general. Also Harofreak00 says his local shop stocks the AC Delcos and he thinks he can ship quickly.
The Great O2 Sensor Test...

thanks. i couldnt believe it though the car ran perfect for 3 days i was getting 50 miles more to the tank of gas and the idle was perfect and everything. today i go down to change my grandmas oil change it real quick. went and started my car and started to drive away and the problem was back. i popped the hood disconnected the o2 sensor and it still ran the same. i guess its back to autozone because i have a year warrenty on the sensor. im ordering a ac delco right now.

the bosch o2 sensors are ***t the problems returned after 3 days so as soon as i get my car back again ill let you guys know whats going on. is it possible my computer is kinda screwed up making the car lean out? or do you think its just the o2. also is there anyway to read an o2 sensor like reading a sparkplug

by the way the car is using a shitload of fuel im only getting about 150-175 miles to a tank and thats driving it sane not speeding or flooring it or anything. the plugs look like the engine is running lean they have a greyish whitish color to them and the o2 sensor was grey also.

OK, I believe that they greyish-white does indicate a lean condition.

Have you checked and cleaned you MAF and Throttle body?

What about your IAT sensor? Have you checked that also?

maf is less than a year old throttle body is clean i pulled it off and cleaned the whole thing out so it looks brand new again. iat is about 4 months old and has been changed since the problem started happening. (second thing i changed once the problem started happening) I had it hooked up to a scanner today and it didnt show anything other then the engine runs lean until it gets fully warmed up but doesnt run lean until it hits closed loop mode. My friends brother said he has no clue whats wrong with it and his scanner doesnt show anything. he said its possible i either need valves ( but he thinks that would make the engine do it all the time even after warmed up) fuel pump (also unlikely) or he doesnt know. If i cant figure this out this weekend the intake manifold is coming off to check for cracks neer the pcv or a bad gasket. Also the problem did start happening after my dad pulled out of a store and ran over the big *** curb with the back passenger side tire. And the next day when i drove the car the problem was there. Is it possible he knocked a ground for the fuel pump or something loose?

btw thanks for staying with me through out all this ****