i have a 2006 Volvo s60 2.5t check engine light on, took it to a shop, they hooked a obd2 up to it. and said that o2 sensors upstream and downstream were bad. So changed them and cleared the code check engine light came back on. Now they say mass air flow so changed it also changed gas filter gas cap had system smoke test for leaks "no leaks" now only 4 of the 7 monitors are ready. did drive cycle 5 times just like it say's still the ..evap catalyst o2 sensor downstream are not ready. Could the computer be bad? can it be tested or buy new one? Very frustrated With this problem And about $500 out of pocket. or will flashing the ECU help?