Inter-related Problems

[01001010]

My truck ( a 96 Disco ) has 122k miles on it. I've got the check engine light on and the "marbles in a can" sound comming from the cats - which has become worse.

Driving home from work earlier, I noticed she started to shift a little late. From second to third, she reved up to 3k RPM which isn't normal.

I think it was our fellow RoverX who reminded me that I should get the cats changed ASAP, as the post-cat o2 sensors would be affected if I didn't.

Now, does the late shifting have anything to do with my most-likely already damaged o2 sensors sending a faulty signal to the ECU, which was caused by the bad cats, hence the check engine light???

I did a search but no one seemed to have this problem. I found Adam in NYC 's thread quite informative but still not helpful enough to diagnose my problem.

All input will be appreciated and considered

[01001010]

So far, I've been told to check my pre-cat sensors because if those are faulty, they'll make my engine run rich and damage my cats in the long run ( already had a long run )

It's also been mentioned that clogged injectors could be the cause of my late shifting.

Hope to here some more suggestions.

[01001010]

Any more suggestions? or advice?

[roverX]

When was the last time you used a good fuel injector cleaner?

Perhaps your cats have clogged up your muffler and the back pressure is effecting the engine?

Take care of the cats asap or port them out as a temporary fix - along with porting the muffler - yes, it will be loud but there will be no back pressure to effect the engine. Don't run your truck for too long that way since the engine needs some back pressure to run optimally.

[01001010]

I'm actually going to poor a bottle of Redline that I bought yesterday, tomorrow when I fill her up.

[01001010]

Ok so I put in a whole bottle of Red Line today before I cleaned it, and after starting it, the engine reved up and down a bit on its own, as was expected and then returned to normal. I haven't driven it since today's wash so we'll see how that goes. I have a 140 mile drive on Saturday so that should get that RedLine flowin.

[dent]

ok, first thing i'd do before you do anything else is change those cats. could very well be all the problems you're having is due to the cats. also advisable to change your pre cat o2 sensors when changing your cats.
i know this is not much help but you could be banging your head trying to figure out this rev problem and all that time, it was your cats and o2 sensor
take care
sam

[01001010]

Thanks dent. I guess I'll be doing that two weeks from today. CTO-6905 is tha part number of the cats I'll be buying from Summit Racing.

www.discountbritishparts.com is charging me $100/sensor. Any better deals out there? ( even though that's already better than a lot of other places )

[John C]

Originally Posted by 01001010

Thanks dent. I guess I'll be doing that two weeks from today. CTO-6905 is tha part number of the cats I'll be buying from Summit Racing.

www.discountbritishparts.com is charging me $100/sensor. Any better deals out there? ( even though that's already better than a lot of other places )

You could get the Bosch O2 Sensors for a Nissan but you will have to splice on the original connector. I did it on my RR but they only lasted a few months. Get the sensors from Nathan, you won't regret it.

[Jonesy]

01 - Check out my o2 sensor thread in the RRC forum - The website I found ships for free - 2 sensors (Ibelieve the same for your Disco) were $150

[dent]

If you're a cheap SOB like myself, just take your truck down to a local muffler shop and they'll just cut the old cat off and weld in some generic. If only 1 is bad, why replace the other that works?
plus those y-pipe assemblies are a chunk of change.
been getting my O2's from Nathan aswell, can't be bothered to do a splice job and is the cheapest i've found. will be taking a look at RRC section for those $150 plus free shipping as that sounds like a damn good price
take care
sam

[01001010]

So I'm heading out of West Palm beach today going back home after spending a whole day there and making it there with no probs, when all of a sudden my truck shuts off while stopped in traffic. I try turning it on again and it does, Revs up to 2500, then comes down to a normal 800 for a couple seconds, and shuts off again. I do that three times before I realize I can keep the engine running if I keep it anywhere over 500 RPM ( as in 500, not 5000 ).

I drove home using both feet to work the brake, acc., and shifting from Drive to Neutral, never taking my foot off the accelerator keeping it over 500.

While driving, I was thinking of what it could possibly be. At first I thought my o2 sensors decided to just stop working, but figured that since I was able to turn the engine back on it couldn't be those. It couldnt be the alternator either and certainly not the Red Top battery. And then it hit me...MY FREAKING FUEL PUMP!!...

When I got home, I took my foot off the acc., the SOB idled normaly. I turned it off and turned it back on and again, it idled normaly...

I put a bottle of Red Line fuel system cleaner in thursday and didnt drive much after that, and today when going TO West Palm I was amazed how smooth El Capitan ( my truck ) rode. Way back was when it all went downhill.

Is this infact my Fuel Pump acting up?

[01001010]

El Capitan has decided to scare the hell out of me...It was a false alarm guys. I guess it was just the RedLine cleaning out the Pump and burning in the cylinders. Just drove about 24 miles to my sister's house and back and worked PERFECT!