Hello so I have an 88 325 and took it to get smogged it failed horrible did a full tune up oil change spark plugs and o2 sensor. had it re-tested and still really bad. I've check for vacuum leaks cant find any and its got a miss at idle but runs fine doesn't lack power. someone said it could be a Cat but thats a pricey MAYBE. if anyone knows about smog and these M20 help is greatly appreciated. Heres the test results...

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