My son has a 1991 Eunos Cosmo 13B RE. He imported it from Japan with 76,000km on it. He wants to run straight pipe but our friendly neighbourhood muffler shop informed him it has a high-end after-market exhaust system. To make matters more complicated he has a coolant line and 02 sensor in a failing catalytic converter. From the shop's experience, if the cat and 02 sensor were eliminated the forcast is the car would run lean and probably be harmful in the long run. Because of the long standing relationship with our family and the fact that the car is rare in our market they will only fulfill my son's request if he can provide information that will indicate success.

My question is: Does anybody know/or have done this conversion successfully? The 02 sensor would be planted in the pipe where the cat used to be I would guess. The coolant line could be blocked or re-routed.

 

It's not a coolant line it's an air line for emissions, that doesn't have to be hooked up unless you're trying to pass a smog check.

If you put the O2 sensor in the new exhaust at about the same location it will work fine, the only problem you might have is that the car will produce more boost with a freeflowing exhaust and may hit the fuel cut.

You can get a little black box that will stop the fuel cut but it'll be hard to find I would think since there's very few Cosmos here.

 

Thanks for the reply Groshuk. Sounds like you're familiar with the set up. Alberta doen't have smog testing (yet). The Cosmo does have a govenor on it that cuts fuel at 200 (realised between Calgary and Okotoks.)