old cars

I'm an old fart. I can work/diagnose/fix old cars. New cars with computer? Put scanner on it, read code, and wonder why an engine needs a crank sensor AND a cam sensor.They work together, if the chain jumped, you will know, real quick. Then I read that cam sensor tells the computer how to adjust timing. Why the crank sensor then? Etc. So you have to take it to the dealer. $$$, And the government with emissions is in on it.
Back in the '70's, Plymouth had just started to the lean burn crappola; I had a problem, looked and traced wires, found that pos, cut it out, threw it away, re=wired, and the engine thought it was a 1968 model. Problem solved.