1995 Ford Aerostar Q&A

1995 Ford Aerostar Question: failed smog test

my 4.0 aerostar has exsessive n. o. reading.i changed the mas sensor and the check engine lite is now out.what other repairs should i do before i retest it? -
Answer 1
the mass air flow controls hc and co. nox is controlled by egr and cat converter. you had more than one problem. have these 2 items checked for operation Roy -
Comment 1
thanks for your reply.i was hoping not to replace the cats as they are high dollar.ill change the egr and see what i get.if it still wont pass ill have to take it to the referee. -
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we failed the smog test we just want to know what could be the problem