Was wondering if my 3.0 cat will work with the swap. Thanks.

 

I had a new one, with an O2 sensor bung, installed, but I don't see why it wouldn't work. I'm pretty sure there are a few people who have reused it. Keep in mind there are two O2 sensors. One before and one after the cat. You'll need a bung welded to your exhaust to accomodate the other sensor.

 

Ya the dual O2 sensors I was aware of but I didn't get the cat with the motor I bought. I called my parts guy at the dealer and the cats have different part numbers.

I suppose I'll try it and see what happens.

 

I don't know what your exhaust plans are, but the stock 3.0 tubing is smaller than the 3.4 systems.

I ran 2 1/2" tubing with Magnaflow cats on my set up, and I'm very pleased with it.

 

Well I don't really know what my exhaust plans are yet either. Regardless it looks like I'm buying a new cat. Thanks.

 

Here's what I did: Sell the stock 3.0 cat to a metals recycle place (put $140 cash in pocket) and by a cheap 2.5" inlet/outlet aftermarket cat for about $60 on ebay, take it to muffler shop and have it welded into new exhaust system. Don't forget a flex joint too.

Next, see P0140 code for cat problem (my 2001 ECU likes to have 2 cats, not one) so buy this: http://www.urdusa.com/product_info.p..._id=1230100014 to fake out ECU into thinking there are 2 cats and they are working perrrrrrfect. All is well now.

 

3.0 cats are OBDI and the 3.4l cats are OBDII if you are trying to pass smog you need a OBDII cat to get by the smog nazis. and those O2 simulators are NOT smog legal

 

I wouldn't spend a lot of money on an expensive OEM cat, they are around $1000 and it may just get stolen. If one cheap cat doesn't satisfy your ECU and you don't want to wire in a simulator, get 2 cheap cats.

If you have smog nazis you probably should think twice about even doing a 3.4 swap. We don't even have safety inspections here anymore, the $5 fee wasn't enough to make them worth a shop doing. But if we do start doing smog inspections they would have to take my dash halfway apart to find my little black sim box. I think most smog inspectors would be tickled pink to see a 93 truck with a shinny new cat in place, no CEL, and no codes stored on the ECU.

 

Well we have smog here so we'll see how it goes.

 

Question (-Dwight)

I dont care about the earth in fact I hate it and want it to die, so I dont want to run a cat at all. I have the precat sensor and plan to hook that up. but dont know If I even should waste my time with the second sensor.

I dont care about CEL lights in the dash, we dont have inspections here, nor do I have to go in for emmisions.

So basically I just want to know if it will run with one Pre-cat sensor.

discuss...

 

really?

no one....

 

Yeah, it will run fine without the rear sensor. Its the front sensor that helps with the A/F. The rear sensor just monitors the cats work.