2 things check engine light/bumping in steering

I recently bought a 95 maxima SE with 97,000 miles on it. When I purchased the car i noticed a bumping when you turn the steering wheel. The dealer told me it was the upper front struts. they gave me 200 dollars off to replace them. The bumping noise sounds like its coming from what i think is the steering box. My neighbor who does some mechanic work thinks its a fluid sound. when you turn the wheel it makes a bump.bump.bump noise but you can't feel it in the steering wheel. This makes me think its definately after the power steering assembly. any ideas?

Also the check engine light came on.. threw the code for a bad engine coolant sensor. I havent had time to check it yet. i reset the ecu and it didnt come back on for 3 weeks and almost 1000 miles. it came back on when i started the car. both times have been when i started the car. This time the ecu threw codes for the engine coolant sensor and the rear heated o2 sensor. these are pretty expensive things to replace. the guy at advance auto said to check them that it could be in the circuit.. anybody have any experience with this. I had an accord with 215k on it before this. I am not sure if i am getting use to the power difference or if it actually does not accelerate as fast anymore. also i figure im getting about 22 mpg at 60 highway and 40 city.

r u sure u r gettin 22 mpg highway and 40 city?? if anything it would be the other way around...

as for the steering problem...your mechanic friend is probably right...its probably something to do witht he liquid, since you can't feel it in the steering wheel

that was supposed to be about 60% highway 40% city. :banghead: thats what i was trying to say. is there anything that you can do to fix that bumping in the steering wheel. anything i should try before replacing o2 sensors and engine coolant sensors?