lx5.0

hi everyone im am new to this forum i just recently got my dream car which is a 92 lx conv 5.0. I went from a import to muscle which was a crx. Well my question was my speedo is bouncing all over the place and its always making like a ding ding sound the car sales guy i bought from said that they oiled up the cable but it didnt fix so what i wanted to know is what else could it be and also would the speedo not working right cause the check engine light to come on

mjr46

most likely it's a bad speedometer head unit= speedometer..replace and retest

lx5.0

ill try replacing speedometer

lx5.0

would the speedometer not working cause check engine light to come on