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So on my quest to clean up my 95 runner 3.0 I have ran into a problem. The old owner deleted the converter but the pipe he used in place of it is a little to short and does not use the correct gaskets. The result is two small exhaust leaks before the stock muffler. I have tried to replace the gaskets with no success so I guess it might be time to bite the bullett here.
My question. Is the exhaust system really that big of a restriction on the 3.0s. Considering this is not a high performance engine I wouldn't think it was that big of a restriction but I am seeing a lot of threads about the piping and stock muffler being a just that.
Second question. What does every one recomend? I would assume somthing like a 2.25-2.50 pipe would be more the sufficient. I would also want to find a very mild 3 chambered muffler since my loud days are over lol.
Noticed an instant improvement when i ditched the factory 2" system for a hi flow 2.5". Definately helped with derestricting the engine. Ive got a 200cell cat, turbo muffler and 18" hotdog. Its not extremely loud, but u know its there. Can barely hear it at idle but its throaty when the foot goes down.
I would only be replacing it from the flange right behind the 02 sensor and back. I have a good 2.5 flow master 40 series in the garage but I am worried it might be to loud by its self.
The Flowmaster 40 is a pretty loud muffler. If you're into that it's great. If you just want a bit more sound than stock get a generic turbo muffler of the right size. If you are cheap and understand that trying to make power in these trucks is a waste of time, just go to the parts store, get all aftermarket stock replacement parts and call it a day. You know they'll fit, they work just the same as stock, and they're cheap. Oh yeah, your exhaust leak will be fixed too, which is the only real issue.
Both leaks are in the aftermarket exhaust pipe that some one put in place of the stock convertor. They didn't use the right flange and made it about 1/8 of a inch to short. So they used generic paper gaskets and double stacked two on both ends to some what manage the leak.
so what is all this non sense I hear about the factory muffler being restrictive? The exhaust has been replaced and repaired in a few other sections and has some sections that look like 1.75 inch pipe. I figured at least I could at least replace it so its all the same size.
i agree about the flowmaster 40. I had it on a 4.7HO swapped Dakota and even with the convertor and FM it was loud. I ended up swapping it out for a thrush turbo that was a lot more mellow.
As for the convertor goes I would not have personally removed it unless it failed. However since this is a beater truck with a lot of miles on a tired 3VZE I don't know if spending $200 in a convertor that may be damaged from engine burn off is a good idea. Especially since a thrush 3 chamber in 2.5 inch is about $40 and a 5 foot 2.5 inch exhaust pipe is about $25. Add $20 for flage and gaskets and your done.
I agree that they have a benifit and should be run on gas motors when they are effective. However with the wear and tear in a high milage motor like this your going to get some excessive oil and fuel in the exhaust that will rapidly destroy a convertor.
I agree that they have a benifit and should be run on gas motors when they are effective. However with the wear and tear in a high milage motor like this your going to get some excessive oil and fuel in the exhaust that will rapidly destroy a convertor.
Just my personal take on it.
Well, it depends. Just because it's high miles doesn't mean it's not capable of running well and clean. My 213,000 mile 3vze is still on its original cat and passes Colorado's emissions test easily. The important thing is for the O2 sensor to be working properly so that the ECU can manage the mixture. But you want that anyway - a properly working O2 sensor and closed loop control will give you the best power and efficiency.
Now, if you have oil consumption and misfire problems, that's another matter, but you need to fix those anyway unless you like driving around with a limping engine.
Working on the exhaust today. Going to try somthing a little different so we will see how it turns out. I picked up a 2.5 inch "cat" and a 2.5 inch inlet/out let thrush 3 chamber turbo muffler. I am going to keep the stock exhaust flange and neck it up to 2.5 from there into the "cat" and then mount the muffler where the spare tire would normally be. We will see how it works out
Fix that O2 sensor mount. That will make your life hell. The O2 has to maintain heat to properly work. Without heat it doesn't work right.
There are videos on line that show the true dyno power gains on exhaust tubing size. I plan to do a 2.5 header back w/o cat on my 88 pickup. It is a 22re and the shop that is going to bend it up for me the owner has the same set up but a carbed 22r trail rig and loves it.
Keep in mind a engine that breath easier doesn't work as hard to idle and there for burns less gas.
As far as my exhaust goes I am using a 8 inch resonator in place of my converter right now. However I am order a universal 2.5 inch cat to use as well. I don't think a 2 1/2 inch convertor will cost any power since the stock one is like 1 7/8s.
id be concerned about how close the exhaust is sitting to the bar for the brake proportioning valve (if thats what it actually is) one decent off-road session and i can c that little sucker getting bent and throwing the braking proportions out of whack?
Good eye. We went back and adjusted it so the pipe runs a little more to the left and sits about 2 inches higher. I will grab some updated pictures once we get the new bumper on and she is done.
As far as performance goes the convertor doesn't seem to hurt it all that much. I noticed a little less top end above 3500 RPMs but it's a very small amount. Low and mid range power seem the same but the truck seems "happy" with the cat. It may be limiting some of the engine and exhaust sounds but the truck seems smoother between idle and 3000 RPMs. Like I said it could just be from the reduced sound but I am happy with it.
06-02-2016, 04:36 AM
