Ok my dad and I got a 1980 fj 40 in ok condition for free...its got 48'xxx miles and is rusted out but it runs ok and evrything works so its ok for a cruiser...(we have had four other 40's so we are no beginners) anyway the muffle rusted out and was lost out on the trail lol...so i was wondering since the cat is about to fall off, before i damage the header can we cut the cat off and run an almost straight pipe with the edition of a muffler all the way back? the reason i ask is with just the cat we have some back pressure problems...i was just wondering if the back pressure problems will get worse if we do this or not?
80' 40 exhaust
- Thread starter Trick450r
- Start date
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stick with no bigger than 2.5" pipe.
the PO of my '79 took the cat off and welded this fine looking 6" dia straight pipe in there...the best part is the muffler putty in holes and the joint cuz he was too lazy to put in a donut gasket. (no extra charge when I bought the truck) The cruiser runs great though...hmmm it is early and and I got no pride....this work of art deserves a pic posted....
Removing the cat shouldn't be a problem at all. On my 79 (which had a cat) I run a header to a custom bent 2.25 inch system that runs inside the framerail, up around the d-side corner of the gas tank and into a flowmaster 40 series muffler, which goes across the back and exits out the passenger side. It's pretty loud on the highway, but it sounds really good around town and offroad. And it's all tucked up so it can't be damaged by stumps and rocks and such.
I have a rounded cylinder welded on where the cat should be..."Is that the CC?" asks the city auto inspector, IT SURE IS!!!!
The old cat you had was most likely completely rusted out on the inside and was totally non-functional anyway. The life for a CC is not really more than 8 years in the best of cases. However, once rusted, the CC will actually restrict airflow from the exhaust and cause you engine to run worse. If you don't have to have a smog check (unless you are billowing black smoke out the back), ditch the CC.
The old cat you had was most likely completely rusted out on the inside and was totally non-functional anyway. The life for a CC is not really more than 8 years in the best of cases. However, once rusted, the CC will actually restrict airflow from the exhaust and cause you engine to run worse. If you don't have to have a smog check (unless you are billowing black smoke out the back), ditch the CC.