Hi.. I just bought my 91 Firebird Formula and when I put it up in the air I noticed the cats were gone! The previous owner did a poor job of running straight pipes on the car. My question to you guys is did a 91 Formula (with a 305/350) come with two cats or one? The way it looks Id assume that there WERE two cats there at one time.....Personally I think it sounds good the way it is but the cops dont seem to agree with me.....

Second...there are metal tubes there were running to the cat(s)...are those oxygen tubes to lean the A/F mixture out or are they to push the emissions out faster???

F-Bodys are completely new to me....as im sure most of you can tell. Ive been driving a 89 Cavalier Z24 for years now. I know GM front wheel drive cars very well. I put a trans in my Cav(auto)..had a engine put in it. I did the exhaust ect ect. Rear wheel drive...manual trans..."nontransverse" engine..this **** is all new to me.

Thanks in advance.

 

the tube are the A.I.R system .. emisson testing (*** NOx) is done in parts per million , so if you add clean air to the exhaust stream , it'll lower your "bad" parts per million and it also helps to burn the unspent gas i nthe cat ..... if you have 2 straight pipes , you had 2 cats ... I believe dual cats was still an option in 91 ..

TVP