So I got a code: 45/ too lean or too rich. How can I find out which one I have or go about fixing the problem?
Info on car...97 LS about 180k, intake,header,exhaust. Last mod was the header and it was installed about 2+ years ago. I haven't cleaned my air filter for the past two oil changes..not sure if that could cause it or not, but I'm just giving as much info as possible.

Also it was hard for me to try and and put the leads from my meter into the plug and look at the check engine light at the same time to get an accurate reading but one of the times I was checking the codes it seemed to get me a code 5: map sensor. But it only gave me that code once so I'm not sure if the leads had good contact or not.

thanks for any help HT