Toledo Motor Failure 99 1.6 AKL Gasoline

Hello everyone, I have a toledo of 99 1.6 AKL motor gasoline, I put the diagnostic machine and the code that comes out is 00668 terminal+30, I get in engine information and not read well or mass of air, or lambda, or butterfly, or lambda resistance etc. I have put the engine relay, and the temperature probe because it didn't work sometimes either, it goes a little better but not at all, you have given you this case, if you can help me, thanks a greeting

Look in the fuse zone and locate the terminal 30 that has a nut, see that it is lazy because the cable is fine but if the nut is already lazy and small current cuts.