Well I welded up my Manifold this weekend and seems pretty successful. Then I was towing my utility trailer up a large highway hill here in town and there was a very loud noise, i though the trailer dropped or lost a wheel. Turns out the downpipe separated just below the manifold joint. yay for me.

so in the grand scheme of things this bumps up my new exhaust project rather rapidly.

so who runs headers. where did you find the best deal.

 

well I did it, place a nice order. Ordered up the Hedman headers and the Magnaflow cat back. Magnaflow y pipe and some o2 spacers. no more cats, no more cast manifolds to weld. Just have to fab the pipes from the Headers to the y pipe and weld a Triangle flange to the y pipe. Can not wait for a proper sounding exhaust and no more rattle rattle rattle buzz buzz buzz leaky sounding exhaust.

 

What little you gained by the headers, you will loose in performance with the 02 replacement. Using them will never the proper information to the ECU, although you can get away with it if you are not looking for a gain.
Think seriously about not using them and replace the 02's.
Also, you will gain a little performance with the headers but if you are really looking for an improvement, the heads need to come off and be port and polished. Not opening up the heads, you will not be able to flow the extra exhaust those headers can handle.

 

plus if you do not wrap them you will increase the under hood temps.

 

First off none of this was done as a performance horse power gain. Manifold was cracked and I welded it. then the down pipe seperated from manifold joint. Now it would be ridiculous to spend money on OEM cast manifolds, down pipes and cats.

the center muffler someone else had previously replaced with what looks like some sort of knock off flowmaster. That is cracked in the middle as well.

Now there is no way that the OEM cats are in tremendous shape after 180k miles.

so the logical choice is to run headers, 190 bucks for the pair with gaskets and bolts. A magnaflow cat back for 445 bucks. A magnaflow y pipe connection for 29 bucks and fab the two connections in between.

I understand what you are saying about the o2 sensors, they are still going to be there. They will be attached to the new pipes in the front with weld in 02 bungs and in the back with angled o2 spacers. like these O2 Sensor Spacer

I am not using simulators.

These are wildy used in all other arenas and can't understand what the difference is for Land Rovers.

Now again if you think I did this because I have some hope and dream that my truck is magically going to become a horsepower machine you are wrong. This was to replace a crumbling exhaust system.

I know my truck is a slow turd and will remain that way. HAHA

 

there is a lot of debate on that subject. Plus loss of life of the header from the wrap.

 

there could be debate? all I know is every car that I ever put steel tube header on always increased the under hood temperatures.

 

Well I guess in the end, spending 4500 + on an OEM set up wasn't going to happen. After all it is MY truck.

Too bad I didn't get an infrared reading before the break, then we could see the difference.

 

I would be willing to bet that the heat lost from removing the cats will be greater than the heat gained from adding the headers. Personally, I would have picked up a used mainifold and rebuilt what was there but good luck with putting your system together. Let us know how it turns out.

 

I agree, it's your truck, do what you please. People sometimes act like these are rare expensive machines, they simply aren't. Headers and no cats will be an upgrade (just like it would for any old pushrod v8). Yes, the ecu might be tricked some and you lose a little performance, but honestly I can't tell. It's still slow, and it still sucks gas like an offshore oil rig. I'd be willing to bet the loss in performance by tricking the o2s is gained back by getting rid of restrictive cats. I'd say it's a wash on that. So, with headers and the cats you may actually get a little power, but again I highly doubt you'll notice a difference other than sound. You obviously are aware of that, though.