I have a friend with a 1991 NA RX-7 that he has been dinking with. He wants to sell it and move on to other projects. He just took it to be smogged. It passed all but the CO test at idle - it is running at about 60% higher than the allowable limit. It does have the orignial pre-cat and main cat (with 114K miles), and a Magna flow exhaust. He does have what appears to be an after market main cat (only this piece, though) that he got with the car. Any suggestions?

 

If you have access to a Haynes manual or factory manual,perform the checks described for the secondary air injection system.The likely problems could be the temperature switch(bottom drivers side of radiator)look for broken wire or corrosion,or a malfuntion in the ACV.

 

Would replacing the stock pre-cat and main cat with the single after market main cat help - assuming this other main cat is newer?

 

It might-all depends on relative condition etc.I use Catco and they work well for 40-50kmiles.

 

Thanks 6 Rotors. I passed today!