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Catalytic Converter Nissan Altima 2003 2.5 Forums > > Catalytic Converter Nissan Altima 2003 2.5 Catalytic Converter Nissan Altima 2003 2.5
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Old 07-13-2017, 12:01 PM
Khalifa1015 Khalifa1015 is offline
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2003 Altima Sedan
Join Date: Jul 2017
Posts: 2
Default Catalytic Converter Nissan Altima 2003 2.5

Ok. Here I go. Car overheated due to the engine consuming about two quarts every 400 miles and I just didnt see it in time apparently, so I had to replace the head gasket be ause it blew out, thinking this would fix my issue with this car drinking oil. It didnt, but as soon as I got the car back the SES light came on reading p0420. I continued to use he car because I really had no choice nor did i have enough money to fix it because I just dropped 1500 on a new head gasket. Well the other day while driving the car just lost power. I pushed the gas and it was barely able to get down the road to the gas station. The RPM wasnt going up high when I pushed on the gas and getting it to acccelerate was just not happening. Im assuming my system is clogged up. Car has 143000 miles and I am on a serious budget. I called a few shops and one guy had told me that even if i replace the whole catalytic system that it will just mess up again due to the engine consuming so much oil. Anybody have any advice for me? Im pissed I got the head gasket repaired when I told the mechanic it was drinking oil and he didnt tell me that it would still do it after i got the head gasket fixed. I havent even driven a thiusand miles on that new head gasket and Im thinking about just getting one of those junk car places to give me whatever cash and take it. But I need a car. Im stuck on what to do. I can probably get together enough to have the catalytic replaced but then what? If the head gasket didnt solve my drinking oil problem then I am just going to run into this problem again in the next few months I assume. Engine replacement is not happening. Ill scrap it if thats my only option. I should have done my research before buying the car off my ex girlfriends uncle, because he knew what he was selling me.

So what im asking is, has anybody had a similiar issue and what did you do? And is that mechanic liable for anything due to the fact I told him it was drinking oil when I gave him the car to replace the head gasket? Im looking at around a grand for the cat repair and id rather scrap the car, take that cash and another little bit of money I have and buy an old honda to get me thru the year until i buy something new. Unless someone else has any advice on after they fixed their cat Im stuck and dont know what to do. Please help. Sorry if I seem confusing im a bit scatter brained right now trying to fogure this out.
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Old 07-13-2017, 06:37 PM
Soapmyster Soapmyster is offline
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2005 Altima
2005 Altima
Join Date: Oct 2012
Location: Oriskany
Posts: 180

Welcome To NiassanHelp
I am sorry you didnt come here first.
Given the oil consumption problem I would not have had the headgasket replaced. That oil consumption is very excessive.
Sadly the 02-04 2.5 engine had a bad flaw. It was not the engine but rather the precat that was the problem.
The precat would fail and cause debris to get sucked back into the engine and score the shit out of the cylinder walls.
This in turn would cause the oil consumption which eventually means RIP for the engine.
I have had a few and they are wonderful cars.
My 2003 has the same issue. The oil gets dirty quickly, I have to add oil more than normal, and I had to replace the Cat due to the oil contamination. The oil contaminates the tips of the oxygen sensors.
I am lucky as I have 230k on my 03 and it still runs like a top, consumption aside.
I also have a 2005 with 320k miles that has never burned a drop of oil and runs like new. Like I said excellent engine but the Precats killed the 02-04 and maybe other years.
Nissan Had extended warranty for the problem and were replacing the engines due to the issue.
I am sure they are no longer doing anything about them by now.
I almost replaced my engine last year but funds fell short so I just decided to keep monitoring it.
If you had known more I would have suggested replacing the engine assembly, even if with a donor from a 2005-06 or up would likely have been fine.
As for where you are now I can only suggest replacing the precat and running a little heavier oil, and a additive for leaks.
That is what I am doing and have had no issues, but if your consumption is that excessive then I am not sure if it will work for you.
I might also mention I mainly travel on the highway and I do not idle at all unnnecessarily and my cat has not gotten plugged.
I wish you the best of luck. Did the mechanic mention anything about the cylinder walls while the head was off?
Who diagnosed the headgasket?
If I went through a quart every 200 miles my hood would be open constantly. I would replace the engine or car if that was the case

Last edited by Soapmyster; 07-13-2017 at 06:49 PM.
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Old 07-16-2017, 11:38 AM
Khalifa1015 Khalifa1015 is offline
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2003 Altima Sedan
Join Date: Jul 2017
Posts: 2

Thanks for replying. Yea man this car has been a pain in the ass. He didnt mention anything about the cylinder walls being scored or anything. It was a local mechanic that a friend of mine reffered me too out here in San diego. He wasnt very great and didnt communicate anything to me unless i asked. What my only sensible option and its the only option I can afford right now, is to order an aftermarket part and replace the manifold myself. Another question I have is, where would it be clogged from this issue and how to unclog it. Is it going to be further down the exhaust line? I dunno what to do about this anymore. Im tempted to just call someone who does cash for cars or whatever and just have them come get it and be without a car for awhile. I dont know what to do. Because if I replace the cat and its just going to screw up again then it isnt worth just buying time until it breaks down again for a thousand bucks. Appreciate the response
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2003, altima, catalytic, converter, nissan

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