A few months ago my girlfriend bought a 1995 ES300 with about 135K on it. We've been rather happy so far but the check engine light has come on and our mechanic told us it was the Oxygen Sensor and that it needed to be replaced. I've tried doing some research and apparently there are 3 O2 sensors, but the mechanic said he couldn't tell which one needed to be replaced.
Another mechanic wants $90 to check which one it is and $200 (Part+Labor) to change it. (Possibly $690 if all 3 need to be replaced)
So here's my question, Can you change them yourself? (If so how) and do the oxygen sensors go about the same time (ie should we just change all 3 now)
I've talked to a friend who owns an auto store and he says that the sensors should be about $90 so changing all three would only cost $270...
Any advice / experience / hope is welcomed.
Thanks.
