Hey guys, I've been browsing this forum ever since I bought a 98 Dak 3.9 5spd about 7 months ago and I had yet to post anything!

To the problem, my Dak has ~ 86k on it and my catalytic converter started rattling something fierce and I'm down to replace it. I know it's got 2.5 in/out pipes on it. My question is, have you guys replaced yours before? What did you replace it with? How much did it cost? Were there performance options like a high flow and it is worth the extra coin?

This is the one I was looking at.
http://www.jegs.com/i/Magnaflow/642/...oductId=750982


And since I'm under the truck, why not add some goodies? Has anyone with a v6 added an exhaust system?

Loving my Dakota!

 

I was gonna suggest that exact one. Haven't installed a cat myself so I cant say how hard it is. I have a v6 with an aftermarket muffler, didn't touch the cat though.

 

On my truck I had the cat go so I just straight piped it since I don't have emissions where I live, as for the muffler I am going to be putting on a flow-master 40 series tonight.

 

I've heard sometimes the high flow ones will still trip the check engine light.

How common is that?

My light is coming on. I was thinking of replacing it with a high flow one because they're cheap. Then I saw the light may come back on. So now I'm thinking I may try moving the 02 sensor to get the light off.

 

When I deleted the cat on mine, I just got two non-fouler plugs for spark plugs and drilled one out to 1/2 and put that directly on the sensor and put the other one in the pipe and screwed the two together and haven't had a code since.

 

Two questions, get that magma flow muffler installed last night? What the purpose of buying non-fouler plugs if the sensor on the exhaust down from the cat only measures co2 emissions? As long as the cat is doingit's job it should be fine. The only way I would see it tripping the CEL is if it does too good of a job and it's not within the acceptable range for the computer so it throws the light.

P.s. I live a few blocks within city limits, sucky but I do have to do emissions.

 

Yes I got my Flow-master muffler installed last night. It was a pia to do and took me almost two hours of banging and cutting to get the old muffler off because it was so rusted on, but now it sounds great As for the non-foulers I put them in mine because I removed the cat completely since it was bad, so I used those to pull the rear sensor up out of the direct stream of exhaust to fool it. As long as your cat is working good and the sensor is good then it shouldn't be throwing codes, but if it is you can try that to see if it fixes it. I think I paid $3 for two non-foulers.

 

Ah I get it, with a straight pipe and non-fouler plugs, the computer still thinks the CO2 output is the same as it would be with a cat because the sensor isn't directly in the air stream. Which would mean, even with emissions testing, the computer wouldn't know the difference and i could pass emissions even with a straight pipe and non-fouler plugs. Well that answers that question! Looks like I'm throwing my money at a new muffler!

Which flow-master series did you get? EDIT: nevermind, saw your signature. I'll update this thread as soon as I'm done cutting out my cat, installing non-fouler plugs, and changing out my muffler.

 

Update! Got my cat off and replaced with a straight pipe and sure enough, computer tripped a CEL saying the catalytic converter efficiency was poor. I'm getting a non fouler plug tonight to put on the co2 sensor so back it out a bit and I should be good to go! I will update again if I have any problems past that.

 

Wish I would have read this post a day earlier. I just installed a new cat on my 99 3.9 yesterday. If I would have known I could skip it and install straight pipe......... Well I'm out $100 for the converter : (

Can you upload pics of the installed fouler plugs? Do you get better gas mileage w/out converter? Any issues?