i don't mean to keep repeating tests but more than likely a bad o2 reporting rich or lean that is fixed that way and not giving accurate measurements to the computer would only happen during closed lope operation if in fact it was the 02 it self and not the circuit to the oxygen sensor or a false reading it should start to idle poorly when the engine has warmed up. i would want to do a vacuum test on the engine to confirm an issue as for the MAF and the 02 if the engine is still setting a cel light when the MAF is not operational then something else is probably wrong with the incoming air into the throttle body or lower. you can test o2 sensors but in this case right now their is no need i would unplug the suspect sensor and see if you gain any performance i know this sounds stupid but if the sensor is faulty the computer should adjust long and short term fuel trim in the absence of the sensor signal versus what the suspect sensor was giving to the engine computer. you can test both mas air flow and oxygen sensors you have a hot wire type mas air so it is ok to use mas air cleaner and spray at the little bobbin. and i realize this is after the cat but you can and will get a check engine light off of a faulty sensor reading but assuming you find any other issues with up or down steam o2 sensors you will have an idea what to look at.

 

Code 136 is the 'rear' sensor bank 1 passenger side..
It does not control fuel in any way..
It's fault is with the 'heater' circuit.
Good luck.

 

under normal conditions the down stream 02 sensors or sensor does not control fuel trim under normal which is not what the poster is dealing with his engine is throwing fault codes po102 Mass or Volume Air Flow Circuit Low Input. and po136 bank one sensor 2 circuit voltage low input. if the down stream oxygen sensor is seeing a fixed rich condition or lower than normal 02 levels after the cat based on what the engine wants or should be seeing it will adjust fuel trim to make up for this condition even if their is no issue with the other sensor. so in some cases the rear sensors will affect the way the engine runs especially when their is a performance issue.

 

Ok I will mess with the MAF some more and see what I can come up with. thanks for all the replies

 

it would be a good idea instead of messing with things to at least see the voltage at the mass air flow at least it would give you direction. if the shop you took it to has access to a scanner or scope they could look at fuel trim incoming air a more in side look at the mass air and 02 sensors and the computer it self and anything related to any evidence you find get some facts before you guess.