How hard to change downstream O2 sensor .I have no access to a lift

 

Per the manual P0430 doesn't mention a failed O2 sensor as the cause. What are you trying to do? Fix P0430 or replace the sensor?

 

P0430 can be a bad aft sensor, but is most commonly an exhaust leak or a bad cat itself. The sensor should not be the first thing to check, ALTHOUGH you can remove the sensor and check for proper exhaust flow through the bung hole, and while out the sensor can be bench checked.
These cars do seem to have an occasional problem with bad cats.

 

Cheaper for me to replace 02 sensor to start.It is intermittent and I can clear it, seems to happen after my wife drives car that this code appears, coincidence?

 

If DTCs P0420 or P0430 are present, this is usually due to the catalyst being damaged due to misfire(s) on that cylinder bank.

If the MIL is flashing, do not operate the vehicle until the cause of the misfire(s) is found and corrected.

 

Runs fine never winter driven , barely driven in rain and under 60k. I plan to change the air filters over the course of the winter , but don't plan on touching mafs. I have a set of ramps if I can change the O2 sensor from under these I will . Exhaust sound hasn't changed at all, no other codes. Whats the price of a an o2 sensor $50 bucks?

 

When I got the P0430 I swapped the O2 sensors from side to side to eliminate them as a potential cause. It was, in fact, the cat. When I took it off there was a rope-like seal that had apparently worked itself out from around the cat matrix (or perhaps it was faulty from day 1) with the result that it covered a significant portion of the matrix and presumably let exhaust flow around it. The code only set on mid or wider throttle openings on an uphill climb. I checked for pricing on the sensors and tried the swap before laying out the cash (which was a lot more than $50). They were not hard to get at.