Well I finally got to look over my exhaust system on my 95 F-450 I bought a month ago. It really feels like the truck is getting sluggish from what it was like when I first bought the truck. I do know the Cat really causes a restriction. There is no hope in heck I'am going to get a 3" down pipe installed I don't know if F-450s are different but even if I took all the heat sheilding off the firewall I still don't think there would be room. The truck has air condition so the box around the heater core etc.

I really don't think I will tempt to change the down pipe its going to require major work on the firewall I really don't want to rip all the heat sheilding blanket off the firewall. I would have to rip out the heat sheilding under the cab etc.

So will I really notice a difference if I eliminate the Cat and leave the factory down pipe ?

I can go to the muffler shop get a pipe made up to eliminate the Cat and have it installed. If I ordered a downpipe it will be around 220-265 dollars Canadain. Having Cat delete pipe shouldn't cost much all I need is a pipe with the flared end to fit onto the down pipe and I can slip it into the existing pipe that goes to the muffler.

For me to change the down pipe and then have a new cat delete pipe installed it will 1 cost me a good chunk of change and 2 will take me all day to just to install the pipe.

So to sum it up should I get a Cat delete pipe made and installed and run with it or just leave it alone ?

 

If your DP is like the 350 and 250 OBS DPs, then, I would hold out to do the DP as well as the cat delete. It sounds to me like it wouldn't take much more time to do the cat delete during the install of the DP. I am sure others will chime in on some good install advice of a new DP.

 

Could it be that your sluggish problem lies elsewhere? Maybe the fuel flow is not enough? I'm not against you upgrading the exhaust, but if it's not the cause you will still have the problem. You may also want to check the EBPV. I think your truck may also have a screen in the fuel bowl that is subject to getting plugged. If you do the exhaust though, I agree with cangim, do it all at once.

 

Having the pipe made for the cat delete will be cheap it my cure some of the back pressure problems for now. The down pipe is the expensive part at 220-265 dollars the 220 is the price BD Power sells them for. If I deal with BD then I could have it the next day because they can over night the part to me or I can go to Abbotsford but shipping is alot cheaper.

It does feel like there is some restriction the truck feels like there is a exhaust brake on when I let off the pedal. I feels like the turbo isn't spooling up fast enough.

It wasn't that way when I bought the truck so it seems like its progressivly getting worse more I drive it maybe its loosening up the carbon. The truck did sit in a dealers lot for awhile it did have engine problems so the engine got pulled and a bunch of repairs done. On some of the bills it says 8 new injectors and engine Re and Re. When I changed the fuel filter it looks a little black like someone has been dumping engine oil into the fuel for lubricant. The bowl was clean no water in the fuel I drained it replaced the filter (from Ford).

I really not sure how a Cat converter works so when it does get plugged up with carbon does it cause restriction. The rest of the exhaust system is fine its not rusted its all well supported it doesn't rattle etc. If a delete pipe will cure some of the backpressure for now I will be happy when I get the dump box mounted on the truck and the truck is making money then I will spend the 220 dollars and upgrade the DP.

 

wow that is the most expensive d.p. i have ever heard of $220 .
i am sure your f-450 is the same as our trucks. i have yet to see and obs superduty that had a different cab than mine for an obs truck. my firewall was very close too. as far as the heat shielding leave it on and your ac box. they are all fine. you will have to get under there though and do some bending of the seam and firewall with whatever you prefer( 2X4, pipe, porta power, scissor jack). i am sure your cat is very plugged up.
ok solution order a d.p. for dale isley at tymar performance. he sells hypermax products. those downpipes start out 3 in. and as soon as it clears the firewall it goes to 3.5 inch . as far as the cat delete either build your own or buy one from him also. i believe for all that i paid with shipping 140 bucks. i have pics of it in my vc's gallery below in the clicky thing.

 

I got mine from motorhaven I think. It was a Dymond eye, two peice, $135 3-3.5" You could possibly do a small body lift if you really wanted the DP. like 2" or so.

I think the cat delete pipe will be fine for you if you don't plan on doing injectors you shouldn't have an EGT problem with the stocker. my '96 still has the stock one. really hard to get to 1200* with a GVWR of 18k pulling a bobcat.

Diesel Rod

 

I'am not going to increase the fuel consumption by adding a chip etc with the price of fuel and 12 mpg.

So do I leave the heat sheilding on the firewall if I do put a DP on ?

I think I will start with eliminating the Cat for now and then it won't feel like there is a exhaust brake that is partially stuck on. I need that 220 dollars to put towards the building of a dump body for the truck.

 

yeah the 450 is the same body as the other trucks it looks liek a tight fit but the 3" will go in with just having to bend that pinch weld out of the way. i would leave the heat shielding on the firewall theres no need to remove it. i would just get a production dp. ive got a tymar in a 94.5 f450 and had no issue putting it in.

 

I guess its just decieving the way it looks as I was looking at it yesterday and its how in the h*** I'am I suppose to get a 3" pipe in there. Bending the pinch weld shouldn't be that bad just takes some work and lots of swearing

 

Is your exhaust backpressure valve stuck partially closed?

 

Contact Piers Diesel Research in Surrey. I picked up a DP from them for $190 plus shipping.

 

i got a dp from dale isley and the instal wasn't bad i used one saws all blade to cut the top of the cobra head off by the turbo and a 2x3 about 8 inches long and a wreckin bar i also made about 6 slits in the body seem it was all very easy don't be intimidated by it good luck

 

I forgot about Piers I will have to give them a call. Usually they deal mostly with Dodge Cummins I did buy a Luk SMF and clutch from them for my IDI 3 years ago.

 

Kenworth,

Your 450 will install a down pipe just liek a 250/350 no differecne at all. Check out site for the aluminized and stainless down pipes and test pipes we have, we can save you some money and ship next day if you want too. You'll be glad you did if you change the down pipe and the test pipe at the same time, weeeeeeelllllll worth it.Call us if you have any questions etc.

Mark @ DPPI

 

I'am a little far away to order from DPPI to drive from TN to here is 2700 miles I caculated the shipping it would be about 120 dollars CND if your part is around 122 dollars if I ground ship it its less but takes 14 days to get here.

So if the part is roughly 150 dollars US that is 175 Canadian add the shipping and taxes etc I will be looking at well over 300 dollars. Its not worth it for Canadian members to buy anything from the US that requires long distance shipping. Its why I have to deal with BD Power or Piers both are in B.C. and both can ship the part to me in 1-2 days ground shipping or day it will cost me 15 dollars.

I looked up Piers price for the down pipe its 187.00 dollars plus tax so it will be 213 dollars plus shipping still expensive plus I still have to buy the Cat delete pipe prolly another 50 dollars.

There is no cheap way around it like I said for start I think I will eliminate the Cat when I get funds I will change the DP.