I got the obd1 codes on the a2 port from my 94 850 turbo auto. I got codes 143 and 315. I went to Matthews Volvo forum and 315 is EVAP system...so where do I go from here?

Then the 143 code means KS knock sensor missing or faulty. I found out after I erased the codes that I should be checking the different ports for other diagnostics.....

 

I take it I need to replace one or both of the knock sensors and the evap valve?