We have been playing with one of our LLY powered trucks exhaust and I thought you people might want to know.

A 4" complete system "kitty-less" set codes. We went back to the stock system "kitty-less" and no codes. We then put a very short flowmaster muffler on it and still no codes. I had this same muffler on 1 of my LB7's and it was too loud. On the LLY it is still fairly quiet. We will attempt to put on a straight pipe next and continue to monitor codes. If anyone else has already done this, please let me know.

sounds good...let us know your results.

I'm interested to see. Been considering grabbing some pipe and doing mine...

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=253216&prmenbr=361

These come in 3.5 inch and 4 and claim to be decent for diesels. You said you used a short one, is this it or is it the one with the offset openings?

Mine had the offset opening. I think this is it.

http://store.summitracing.com/default.asp?target=/egnsearch.asp&N=400238

I'm not sure, I bought it in 2001 and the diesel specific mufflers were hard to find then.

We have been playing with one of our LLY powered trucks exhaust and I thought you people might want to know.

A 4" complete system "kitty-less" set codes. We went back to the stock system "kitty-less" and no codes. We then put a very short flowmaster muffler on it and still no codes. I had this same muffler on 1 of my LB7's and it was too loud. On the LLY it is still fairly quiet. We will attempt to put on a straight pipe next and continue to monitor codes. If anyone else has already done this, please let me know.
You do know I have a cure for the EGR codes.......

Why would you introduce back pressure to the system just to cure codes?

What this DOES seem to prove is that the straight through mufflers produce best flow and the offset variety that supposed to produce more power than a straight pipe do not deliver.

2005 LLY KD4-5 full exhaust EGR has been unplugged since day 1...

Some day I may even get around to trying Fingers' mod

Kennedy did you block your egr?

Why would you introduce back pressure to the system just to cure codes?

What this DOES seem to prove is that the straight through mufflers produce best flow and the offset variety that supposed to produce more power than a straight pipe do not deliver.

2005 LLY KD4-5 full exhaust EGR has been unplugged since day 1...

Some day I may even get around to trying Fingers' mod

:iamwithst

You can get rid of codes by sticking a potato in your muffler too. :eek:

There won't be a "painless" cure for it until someone releases a tuner that deletes those error codes. This is what we currently do with the LSx gasoline engines. Codes that are created by performance modifications you simply remove through programming.

For now, take advantage of the hard work Fingers did to help us all out.

Guys, I tried a 4" exhaust and was not happy. It looked like a decent setup, but it was a cheap purchase. It threw the codes and hurt my fuel mileage under the excact same driving conditions. I don't know if the exhaust or the codes were the problem. The exhaust might have helped, and then the ECM attempted to compensate causing the poor fuel mileage and the codes. I was just trying to find out how far I could go without upsetting the factory ECM, and what results I would get out of it.

What I am doing cost me nothing but labor. Kennedy, I have always trusted what you say. Your integrity seems spotless, but I am sure you are not going to let me try 1 for free. Fingers, I have watched your posts also. I am convinced that your "fix" works, but once again I would have the cost of the exhaust, and your product. Mcrat, I agree totally with what you say. I put a TPI on my boat a couple of years ago, and TPIS did a custom chip bypassing the speedometer, cold start, and egr codes. I also think there may be some advantage to a program written specifically for a Dmax with a 4" exhaust and an air intake. With all the compitition out there "tuner wise" I can't believe they are missing the advantages of this stuff.

On a side note I have also blocked the EGR in my tests. I found a very small drop in initial operating temperature, but it would still build the heat on a hard pull. I also noticed more irractic fuel mileage. Sometimes it would seam better than it should and sometimes it would be worse. I have since installed an EGT gauge in one of my LLY trucks. I will soon add them to each truck. I will block the EGR again just to see if there is a EGT benefit when I stop playing with the exhaust. I Thank every body for their input and opinions and please keep them coming!!!

I have worked with Edge and Quadzilla, because of the amount of miles I drive on a regular basis. Quadzilla has a new program for the reflashed trucks. I will start testing on this next week.

I guess what it boils down to is I like to tinker. I have not found anything that truly helps the LLY fuel mileage. Power is easy to come up with. I am trying to do a balancing act for power, reliability, fuel mileage, and of coarse, cost.

Kennedy, I wish I was closer to you. I would love to spend some time on the dyno, just to get around my seat of the pants testing methods.

I saw the specs for the gas predator it can disable a bunch of codes such as ones from removing the cat and stuff. Like you say, why doesn't it do that for the diesel? That would be really handy.

I hope I am not speaking too soon, but I put a MBRP exhaust on over the weekend and have driven about 75 miles, with a least 10 re-starts and so far no codes!! The truck runs nice and sounds nice, but at an idle it has a high pitched exhaust noise probably from the turbo. Did I mention I dropped the kitty? Yes, and no codes!!

:ro)

I am planning a blocker, finger stick, and Hypertech before the weekend.

cadent45, the codes do not turn on the service engine soon light imediatly. Run a diagnostics tester on it if you can and please let us know.

I haven't blocked my EGR yet, and not sure if I will till summer. I figure even if there isn't flow through the EGR, there's still heat transfer.

Never once had SES light on for EGR, but that is likely due to Fed emissions.

OK guys, here's the latest. The straight pipe "kitty-less" system is up and running. Still not as loud as my wife's LB7 with a 4". Has a fairly good rumble under normal driving. Under heavy loads it does tend to sound like 50 vacuum cleaners on steroids. So far no towing, but a full throttle stomp with a 100HP Predator at the top of 4th gear is 850 degrees on the EGT gauge.

I haven't blocked my EGR yet, and not sure if I will till summer. I figure even if there isn't flow through the EGR, there's still heat transfer.

Never once had SES light on for EGR, but that is likely due to Fed emissions.
I think I might unplug mine and give it a try for a few weeks. I'm debating about the 4in exhaust too.

Don't be shy;) I think I might unplug mine and give it a try for a few weeks. I'm debating about the 4in exhaust too.

I just unplugged the egr. I'll see how it works on my truck in do time.

Rick, where did you get the pipe that replaced the 3.5" muffler? Was it a clamp on, or did you have to weld it?

Thank, Rob

IdahoRob, I used parts from the stock exhaust off my 01, and welded it on. Somebody may make a "bypass pipe". Hopefully a vendor will pipe in.

I just purchased the MBRP exhaust for my 05 LLY. It came in the box as a system install without the kitty. I had assumed it would come with the bolt up bracket like on the stock system. It sounds from reading this thread and others that I'm going to get codes if I install without the kitty. I'm also concerned about what will happen when I go for emissions testing two years down the road. Any advice on what I should do? Cadent did your install work w/o codes still? Rickd, I believe you also said your running a straight exhaust w/o kitty on your LLY w/o codes.

I had a conversation with Superchips the other day about the codes problem. They told me that if you installed A superchips Microtuner on the truck and the SES light comes on contact Superchips to send the unit back and they could calibrate the tuner to rid the check engine light.
To all DieselPlace members, for great prices on Superchips call Toll-Free 888-329-8963

Karl Levy
All About Diesels
www.allaboutdiesels.com

Hoghunter, some do some don't. Its the luck of the draw.

Hog Hunter

Sounds like you have purchased our " off road" exhaust systems.Our regular DMAX exhaust systems does simply bolt up directly to the four bolt flange at the back of the stock front pipe. If you are concern about convertor laws you may want to check back with the dealer where you purchased. Be sure you have what you really want before you install.

Thanks
MB

MBRP,
sounds interesting. I did not know there is an Off Road version without the flange and complete front to rear. How much is that for the 2005 in 409 SS?
Thanks!

MBRP, I sent you a PM but I don't know if you've read it. Basically, I decided to go ahead and install the system that was delivered and remove the kitty. I plan to retain the kitty and put it back on if needed for emissions in two years. I saw a PDF instruction file on one of vendor websites that shows a "slip joint" with a flange on it that looks to be used to bolt up to the flange that comes off the kitty. Could I buy that piece seperate and if so how long is it? The downpipe that came with the system extends beyond where the kitty ends so I would need to go back to the end of that pipe to make the connection.

I had no codes on the Predator, but 5 "unregistered" EGR codes on a Tech II w/ multiple logs since install. Cleared all again last week, 2 are back already, and never did see the check engine light come on. Can the "Fingers stick" REPLACE the feed if the entire EGR system is removed and blocked off? ...T

Stick needs the EGR valve motor to work. It can not replace the EGR feed.

Update. I do get an occasional code from the exhaust. Seams to be very random, to the tune of about 1 a month. Never any check engine light. Max EGT so far at 1250-1300 degrees. 28,500 gvw up hill, bucking wind.