Volvo Repair: 1990 volvo 240DL, hold button, posion

Question
My name is Mark and I need help on 1990 Volvo 240DL runs at idle but bogs down on acceleration There is a check engine light too. New air filter,fuel filter,plugs,plug wires and cap & rotor were installed. Is there a way to check the code without a tester? And is there any other suggestions I may try.

Answer
Mark, sounds like an  air mass meter.  There is a diag port on the drivers firewall.  Turn key on, Put pin in pos 2.  Hold button for 10 seconds.  Count the flashes.  Example; 1-2-1, then hold button again for 5 seconds and read next code.  do this until the first code read reappears.  Then hold button for another 10 seconds.  Wait for steady light, then hold for another 10 seconds.  Code is now clear.  Do the same procedure with posion 6.  Let me know what you find.  Roger