I have an 86 xl 4x4 and am redoing the exhaust and there is a tube connected to the pipe just past where the two pipes from the manifolds meet. Some places I've looked say its okay just to take the smog pump out because it robs power and is useless, but others say that it can affect how we'll the engine will run. Suggestions?

 

Depents on your engine and location. If its a 300/6 DO NOT remove it. V8 carbed should be fine fuelie v8 probably ok too. Although if its working i would leave it be. It just recycles some exhaust back into the mix to reburn it. Actually it technically could hurt mileage a bit if you remove it.

As for location if if have to pass a sniff test id leave it.

 

It's the 302 EFI and no emissions are required here so I should be good to just take the whole thing off?

 

Yep. Just plug off the return pipe from the exhaust. If not it will give you a buzzing sound in the cab.

 

So I was just debating the same thing.. But I read what you guys wrote so I left it alone but just out of curiosity why such a deff no no on the 300-6?

 

It really depends on your year. I think 83~86 (might start in 82 or 84) has a feedback carb. If everything is working and present it works ok but if 1 piece of the emissions system breaks or removes it can "lock" the distributor at 10° timing and it wont advance or retard on its own. The only way to fix it is revert back to the ds2 system of the pre81 300s. Then your stuck with not reaching full power and only getting 12~13mpg.