I had a similar experience trying to smog my ’88 jeep. Online the catalytic converter (cheapest I could find) was like $279,add to that the installation and you’re around $400. So i called the local parts places, found it at NAPA for like $179, went in and the manager knocked off another $30 bucks. Had my neighbor weld it in and passed the test better than it ever had since I’ve had the car (16 years). So now I can sell the car, but I love it so much that probably won’t happen anytime soon.