i agree somewhat with the above reply. i have seen cars with real problems and those with volvo dementia. i would pull the fuse for the system. this clears the codes and resets the adaptation. if it repeats, with the same codes, let's look at it. if the codes are different, maybe 1 is the same, then reset and go again. i had 2 cars i did that with for 2-3 months. the 90 240 got a new brain-dementia-and the 89 16v 740 got a new mass meter. gee, a real problem. be aware that if the code for, say, coolant temp snesors pops, that does not mean replace it and the problem goes away. the circuit is affected, sensor, wires, ecu, etc. you'll go broke putting in o2 sensors for all those o2 codes. good luck, chuck.