I have a 1987 Dodge Dakota with the 3.9V6 with 212K on it. I've been trying to figure out what to do.

My emissions pump has the belt disconnected due to severe sqealing and there is backpressure coming through the system. The air injection diverter valve leaks exhaust gasses. It did this before the belt was removed, but I'd guess it is a little worse now.

According to what I just read in another recent thread, disconnecting the belt will cause the check valves to fail and cause a lot more problems.

In researching the parts to rebuild the emissions system, it looks like it will run approximately $200 just for engine parts (pump, diverter valve, egr valve etc) then it will require a new cat.

The exhaust is in rough shape and needs to be replaced too.

This brings me to two questions:

1) Do I just rebuild the stock emissions system?

or

2) Do I remove the emissions stuff (that doesn't work properly already) and plug the manifolds? Then, when replacing the exhaust, just use a standard cat rather than the type that requires the air pump inlet? Basically spend the $200 towards building a better exhaust.

My Dakota is a carbed model so I don't really have a complicated computer to deal with but there is some sort of box mounted on the passenger inner fender and I do have O2 sensors.

Any ideas? I'd hate to waste money when it could be spent elsewhere but if restoring the original system is the best, I can do that too. It just seems like I could rid the engine bay of a lot of complicated components and clutter by eliminating the smog pump and related parts.

 

if you dont need to go through emissions, then just removing the cat and pump and plugging the holes in the exhaust then installing a regular cat will work.

 

I was thinking about going that direction and installing a free flowing exhaust and performance muffler and cat.

The stock exhaust on my Dak is pretty small diameter, maybe 2" at most. I figure a 2.25" or 2.5" would be better for flow. I know these sizes can be found on the later Dakotas.

 

what i did, before i swapped the motor out of my 91, was changing to 92 manifolds(yes they are direct bolt on) and went with a 2 1/4 exhaust with no cat and a cherrybomb muffler. sadly the motor never ran with the new exhaust because the pcm went bad from age

 

I was looking at upgrading to the 92/93 V6 manifolds but the gaskets showed different part numbers so I figured they were not interchangeable with the premag vs. magnum V6.

Sounds like you did exactly what I'm thinking about doing.

 

it was a direct bolt but I didnt use gaskets. the only thing is if you get the newer manifolds then get the y-pipe for it also.

 

That looks like the way I will go.

I'm going to get a set of '92/'93 V6 manifolds combined with the matching Y-pipe. I will use a flow through cat and a 2.5" replacement exhaust/muffler set up. The V6 should breathe a little better.

I did notice that there is no port for the O2 sensor on the '92/'93 manifold that my 1987 manifold has on the drivers side. I might have to tap a hole for it.