Late Model '40 Exhaust Question

Sep 19, 2005
Salt Lake
I’m looking at putting a new Exhaust on my '81 FJ, over Thanksgiving (it currently resides in Michigan). I live in Arizona (SMOG testing sucks), can I realistically run an exhaust system without a cat and still pass emissions, or should I plan on running a cat? Also does any one make a kit with headers and a cat? This may have been discussed already, if it has please point me in the right direction.

Thanks In Advance!

John Smith

In the garage
Jun 7, 2004
Whether or not you can pass depends on what type of emissions testing is done in your local. If they do not do a visual for a cat and only do a tailpipe sniffer test then yes you can pass with flying colors. Simply add a gallon of denatured alcohol to about 1/8 tank of gas and go get tested with a hot engine.

If you have a cat you can fully desmog a late model 40 and still pass a roller and tail pipe test if it is tuned correctly.

If you want to run a header you are going to have to desmog unless you buy a header with a EGR connection. A few vendors sell this type of header. You can have any decent exhaust shop bend up a cat back exhaust. Anything is better than the stock setup that goes under the framerail on the 79 and later 40s.
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