Catalytic Converter Removal

[speedgray]

Hello: I’m new here; just joined FCA. I have a 1983 Spider 2000 which I would like to remove the catalytic converter and replace it with a “test pipe” permanently. Does anyone have any experience doing this, and does it effect overall engine performance?

Thanks for your help.

Speed Gray
Grand Rapids, MI

[Fiat500USA]

Welcome to the forum and the club. I've deleted the catalyst on every older Fiat I've owned and there is no real downside (other than emissions testing). The exhaust will be louder, but that's not usually an issue with a sports car. You'll get a slight bump in power too. Likely more notable in the higher rpm range.

Check out AutoRicambi and look into getting a dual outlet exhaust manifold (if you don't already have one) with matching downpipe for a bump in performance. The LJetronic injection kinda limits things but the manifold and cat delete will help.

[speedgray]

Thanks for the reply so quickly! Your summary was what I had hoped. This car has been sitting for 20 years, so I’m going to take it a step at a time in getting it back on the road. Beside the cat conv, the other “big issue” is new tired and a badly needed front end alignment. We have no emissions testing in Michigan, so pulling the converter won’t cause a problem.

Thanks for the info . . .

[map]

I'd probably get it running well before making any mods, though. Before driving, I'd also swap out all the fluids, including brake fluid... and keep an eye open for brake system problems.

[Fiat500USA]

The first thing you need to do on an old Fiat is to change the timing belt if you don't have confirmation of when it was done last. This needs to be done every 36,000 miles. There Isn't a year interval specified, but the rubber deteriorates so the safe bet is somewhere between 5-7 years. The timing belt tensioner must also be replaced. Besides the aforementioned fluid and filter changes mentioned above, all the belts and hoses need to be changed, including fuel hoses. Siphon out the old gas and put fresh in, too. if the gas tank is rusty, get a new one. Clean all your ground connections and add another engine ground.

The cat is likely deteriorated so getting rid of it is only going to help. I worked in a shop that serviced and restored these cars and we ALWAYS desmogged them (even when they were almost new). Bringing them back to European specs (or as close to them) is the secret of a sweet running Fiat. The late model injected cars ran a lot better than the smogged out carb ones, but every little bit helps. The US cars have like 30- 40hp less than a Euro car.

[speedgray]

Hey you guys . . . I really appreciate all the suggestions which are being brought up and I intend to follow most of them. Didn’t know abt the need for timing belt replacement so I’ll add that to the list. I want to do this “restart” properly and correctly. This car is in almost perfect condition cosmetically, and has never seen snow or bad weather.

I see the vendor listing on the FCA home page. Any preference or recommendation as to who to get parts from? My first order should be substantial; belts, hoses, plugs, fluids, etc etc.

I remember this car overheating easily, and comments on this? Is it typical or is mine got a problem?

Thanks again for for the support and advice!

Speed