take a look at other Ds in the area if you can, if you get too small of a cat it will cause problems with running down the road, the replacement should be approximately the same size as the original stocker.

 

Ok this is what you should have with a regular non California model. You should have both down pipes come together mostly on the passenger side with a Y pipe. So in other words I think each down pipe is 2 1/4" then goes into a 2 1/2" at the Y pipe then continues out in 2 1/2" pipe as OEM.

What I would do to correct it is, you should have that "Y" pipe made into a 3" outlet then go 3" all the way out. So you then install 2 Oxygen sensors before the CAT, one on each down pipe mid way before the "Y" pipe. Then you need to get the correct CAT because if you go too small it wont work correctly! You NEED to get the right size CAT! I know of people that bought that cheap Magnaflow CAT and it was too small. Magnaflow's web site states you should need part number 99006HM for the 2 1/2 " pipe which is stock, however if you do the 3" system you need part number 99009HM I would assume as it has the same body just 3" in and out. Call them to confirm.

Anyway after the CAT you put in a single Oxygen sensor down from it about 6"-12" then into your muffler then your tail pipe. So total you have 3 - O2 sensors. One on each down pipe and 1 after the CAT. Now I would do it in 3" all the way from and including the "Y" pipe out.

 

Thx, when my mechanic calls to give me his prices and tell me what he thinks needs done I'll know if he is doing it right.

Hope he calls soon. I been pacing around like I'm in a hospital waiting room.

 

Talked to my guy today, he had to order the y pipe and it won't come in till Monday. Told him the cel was not working, he hooked it up and it was throwing two codes. O2 sensors.

 

That makes sense since you had no O2 sensors in the begining. Is he going with the stock 21/2" or 3" as suggested. I purchased a second D and both of mine are still original so would like to know how everything goes. I am thinking of the 3" system on mine and my sons.

 

Still waiting to get it back. I'm way out of patience with this guy, 8 days seems a bit much for an exhaust. Bought the thing 2 weeks ago been at the shop 8 days of that. The gut is a friend of a parent so I don't want to MF him just yet, but he needs to hurry.

He did tell me that it had one o2 sensor in each pipe coming out of the manifolds, I'm not sure exactly where they were mounted, I looked from on top and from underneath before it went and didn't see them.

I'm afraid that it was a 4 sensor setup now. And maybe there were a couple simulators somewhere that went bad from sitting. So if my mechanic is decent he should know what's up by looking where the sensors plug in? Would be 2 or 4 places to plug in sensors? And that's where a simulator would by mounted somewhere?

P.S. will be the last time I use this guy I think. Prices are cheap, work gets done right I think, just takes way longer that I'm told at the beginning.

 

There should be 3 O2 sensors, since there is only one cat there only needs to be one post cat O2.

 

Don't worry, he'll get it and it should be right. But 8 days is just a bit much I agree. I had my Magnaflow CAT back system built and installed in about 6 hours or less? It was done after work so I really don't know when it was actually done. Wonder what is holding him up?

 

Well I got it back tonight. Ride home was good then I took it back to town and its still doing the same thing. Wanting to stall at some not all stops, then it seems like it corrects itself and revs up and I gotta push hard on the brake to keep from rear ending the guy in front of me. Backfiring inside the engine and sputtering.

Remember cel doesn't work but I probably got some codes so I'm going back to his shop in the morning to hook it up. Was throwing o2 codes and he said he found 2 o2 sensors on my system before he worked on it and reused them. If its throwing the 2 same o2 codes then I will replace them.

Here's what he did, now I have a y pipe from manifolds, then the pre o2 then the cat then the post o2 then split back to the 2 previously installed glass packs then duals out the back. I think someone mentioned there should be 3 sensors?

It's acting exactly the way it did before, I just now have less cash in my pocket and my durango doesn't sound near as mean.


EDIT: I think instead of saying Backfiring in the engine, I should say repeated popping in the tb. Put it in neutral shut it off, restart, put it in gear and it takes off smooth as it should.

 

Damn think I see the problem from reading this page again, needs 3 sensors. Are the plugs for the two pre cat sensors near each other so I can point that out to him.


https://dodgeforum.com/forum/1st-gen...ngo-5-9-a.html

Here it says only one pre, between y and cat