Hey man, sorry to hear your troubles...

I had a 2003 Range Rover that had multiple misfires - turned out to be leaking intake gaskets... you could do a smoke test or brake cleaner test to diagnose this for little or no cost.

Also, someone mentioned your cats could be the cause of the misfires, not the misfires causing the red hot cats - this is a good point and it's possible you could be tackling this problem from the wrong end. Might be worth disconnecting your exhaust pre cat and seeing if this clears things up - it'll be noisy as hell but again it's another cheap diagnosis that is worth doing rather than throwing new parts at the problem.

FWIW, methodical troubleshooting is the way to go - I've thrown parts at a Land Rover before (2003 RR) and ended up throwing good money after bad until I gave up on the truck. Had I known then what I know now I would have turned more to forums like this one more often - sure owuld have saved a lot of $$ a grief. You don't seem to mind getting your hands dirty so stick with it - just don't buy any more parts or accessories until you do some methodical troubleshooting and I'm sure you'll figure it out!

 

Very good point on the cats. If I'm not mistaken you have upwards of 140k on your original cats. That's beyond their expected lifespan

 

Hmmm Ive never heard of cats actually causing misfires but Im interested in your suggestion about disconnecting the cat from block to see if the misfire persists or not. Never worked on exhaust before but Ill give it a look over and see how exactly it disconnects and give it a shot. Thanks so much for the tips. Tempted to take a day off from work so I can dedicate an entire day to diagnosing ****. I also understand what you guys are saying about the need to refram from throwing random new parts in until I know for sure thats the part I need. I will try the exhaust thing first and see if that changes anything, if not than I will swap the ignition wire on cylinder 6 with the old mag wire. If nothing still ill swap the coils around and see if the misfire follows. Thanks everyone for the support.

I hear what you guys are saying about the pre OBDII vehicles. Still lately I find myself intrigued and really wanting a classic long wheel base 4x4. Maybe I wont sell this vehicle, I just get so dam mad in light of how much Ive invested. But my next vehicle just has to be a classic. Even though it will be harder to diagnose as you guys say, still less computers, less sensors must be a good thing. I saw a video on youtube from Andrew White; he meets up with a group of English Land Rover Defender/Series owners and talks about OLD VS NEW. He asks them if they would trade in their old Defender for a new one (with all the gadgets on board) and they said NO! One owner used a mouse trap as an example of how easy it is to work on and repair a old Defender lol.

 

Good luck disconnecting your exhaust. Its its original and your frame is rusted out I'm thinking the bolts connecting your exhaust are probably nasty. Maybe you'll get lucky though and your mechanic will have disconnected it so it will be easy?
The other issue with disconnecting your exhaust is you will need to drive your truck to confirm the codes are gone. Bring some ear plugs.

 

There's a big discrepancy in philosophy of use between yourself and the kind of classic 4x4 nuts that you're mentioning. In short, they don't have what you would consider a normal life or even a job. Their idea of a daily driver might be what they use the putt around the game park, drive to the back of their vineyard to check on the irrigation, or maybe just down the local Memorable Order of Tin Hats.

You're already a fool to squander so much of your income on a practically useless machine when you've got far more significant things to be saving for. I don't intend that to be taken too personally. Most of us here are afflicted with the same foolishness, but you're a damn fool to think at the lowest moment that you ought to double-down.

The old Classic is just fine if you want try extra hard not to look pretentious whilst driving around Martha's Vineyard. But if you get creamed on the turnpike, it's really not what you want your family to be in. It's definitely not what you want for your kid's first car if they have to drive on a freeway -- around the farm, maybe.

I don't know if you have a second car that's more practical, or if you have anything saved for a house, or to spend on anyone but yourself, but I suggest considering those things before you decide to get deeper into vehicle projects.

 

I disagree with this statement, although I understand where the advice is coming from. Most people would not spend the bulk of their savings and income on a vehicle. OP is clearly not "most people".

The USA has a fine tradition of folks taking off to explore just because they can. If nothing else, the life lessons learned can be extremely valuable. One last point. The time for adventure is when you have less commitments, before family, mortgages, career etc. the guy is working his *** off pursuing his dream. Not yours, and not mine. Regardless of whether you agree on his choices, the world is a more interesting place with folks who follow their dreams in it.

 

Thanks so much for the support Robert Booth.

There is something about the Discovery model, something about my D2 that inspires and motivates me to do the best I can, not give up and dare to go places few have ever been. This truck has instilled in me a dream of traveling great distances, to see grand landscapes and experience new things. This has also played a major role in my work ethic. Never have I worked so hard at a job or been so dedicated until I bought this truck back in late 2012. All the things I wanted to do with this vehicle, I knew there was just one way to do it - WORK. Busting *** on a ship or in a seafood processing plant for 16 hours 7 days a week for afew months straight is no easy feat, but the dream of going places in this vehicle and an image in my head of what my truck will look, feel and be like when its 100% complete kept me going. Its hard to explain. No I dont have a family or a house or any big responsibilities - yet. I guess you can say I'm a nomad. Frequently moving around, taking contracts, traveling often between the east and west coast for odd jobs etc. I want to settle down and find a wife and build a cottage in the woods, but not now. Not until Ive been out in the world and seen alot of things on my terms in my truck. This truck is the ONLY evidence of my hard work in Alaska because I put most all my income into this build. Its kinda pathetic I know.... but its all I have so I try my best. Sometimes bad **** happens though and I feel the urge to set the truck to the torch and walk away. Its a dream and thats why I do what I do. I also dream of becoming a Land Rover Independent mechanic. Id love to have a job restoring older Land Rovers (1948-2004) and fitting expedition/off road equipment to new Rovers etc. I love that kinda **** and it makes me happy. But I have to start somewhere and the beginnings will no doubt be humble.


FishEH: Ive been thinking about the exhaust bolts myself and agree with you. I imagine the mechanic had to have disconnected the cats recently but still the bolts are probably rusted to ****. I think Ill start with swapping the coils around to see if the misfire follows. While im at it I need to learn where the injector wiring is and inspect each of them to ensure there is no loose connections or damage to the wiring.

 

Wow, Binvanna. Opinions are like Sheriffs; every county has one. Since the OP saved for months for this project I bet he's got his own finances planned and sorted. Not that I disagree with everything you say, but there are people who buy Discos for a couple thousand dollars, trash them even further, then toss them. There are people who just like them. There are people who bought them new and have more than 40K in them. There are enthusiasts. There are all kinds of people. I don't think any of them are fools.

I missed the earlier red hot cat issue. Cats can cause misfires when they are clogged and interfere with the flow of exhaust; this makes it harder for the engine to push exhaust gas out of the valves and manifold. They can get clogged with gunk from the engine or, more likely in this case, when they disintegrate. I know that antifreeze will cause them to disintegrate. Alot of gas from misfires will, too (personally experienced by me). Excess gasoline is burned in the cats. If there is alot of gasoline or combustible hydrocarbons being thrown in the cats, you get red cats and when they are red they are probably breaking down. Efficient or even semi efficient cats shouldn't be red hot. That excess heat is going to be real bad for the driveshaft and frame. I have drive mine with the exhaust dropped, just as a test. My neighbors didn't know it was me (or maybe they did) and called the POLICE. It rattles widows. It scares babies. It curdles milk. It's not good.

If your cats are getting red under normal conditions, I would drop them att the exhaust manifolds and idle it to see if the codes come back. I did this on another vehicle after the dealership told me they needed 15K deposit for anew engine. I am still driving that vehicle with the same engine (6 years later). You might only need a cheap Y pipe. The idle, without exhaust, is loud but not deafening. A slight touch on the accelerator will result in the police being called.


You do have some rust, but you live up north so that's normal. And your engine was recently installed. I think if you spray some light oil on the nuts and studs where the exhaust meets the manifold you will be find out if the cats are a problem in about 30 minutes worth of work.

 

I understand how cats can get damaged with to much fuel entering the cats and being burnt. My concern right now is that if it turns out I need to replace the cats, but the misfire is caused by anything else and thus proceeds to damage the replacement cats. Can you elaborate on how bad cats can cause engine misfires though? What is stopping bad cats from creating misfires in all cylinders? As it stands Im getting cylinder 1, 6 misfires.

In any case its raining heavily today so I wont be doing any work on my truck today. I still want to flip the coils around and see what happens with the misfires. Man I wish the coils could be relocated to a spot where they are easier to play with and thus make it alot easier to replace ignition wires. What a stupid spot on the back of the intake manifold for coils.... I noticed that older vehicles had a distributor. I wish a distributor could be retrofitted to the D2.

Thanks much for the support mate. I will keep this truck. I will do my best to figure this issue out and deal with it, if the cats completely fail or all my attempts to figure out the misfire issue fail than I will have my truck towed to DAP/Performance Unlimited.

 

If the cats are clogged they restrict the exhaust flow and create back pressure on the engine. So when the exhaust valves open, there is nowhere for the exhaust to go, causing the engine to work harder to expel exhaust on the upstroke. In worst case scenarios the pressure could blow past the piston rings or the head gasket and any number of other gaskets. Basically, it is like putting a banana in the tailpipe.

I should mention that conventional wisdom is that some backpressure on gas engines (but not diesel) is needed for good engine function and that the valves can be burned when you have too little backpressure, so running it without an exhaust for long or at high heat is not a good idea. I don't know why that is the case, but conventional wisdom is usually conventional for a reason.

If the cats are truly fried you can just get rid of the cats, if you don't mind breaking the law. I've done it for experimentation purposes only on a bad y pipe. It will cause your rear O2 sensors to be upset, but not much else. You'll get more power, slightly lower gas mileage, and more noise because of the shape of the catalytic converters. I don't recommend it, long term, and I speak from experience there.

You can also weld in pipe where the cats would be, either concealed in the cats or in place of them. The passenger cat gas an offset from he inflow to outflow so it would be difficult to do but an outlaw muffler shop could handle it.

The catalyst in is a white or gray, brittle, substance like a brittle cake that is easily broken (like with a screwdriver or a drain snake) and blown or vacuumed away, if you can reach it in the pipes. When you look at it, it is amazing that exhaust transcends it at all. You wouldn't want to breath the dust.

When the cats clogged in my Titan due to a bad spark plug spewing gas, it would not go over 7 miles per hour and showed misfires on all cylinders on that side.