Ls400 Catalytic Converters

[Jacob]

Hi everybody,

I recently bought a ’96 LS400 with 113K on its odometer. The car sounds good except for two things the check engine light is on, and the engine vibrates around 2000 RPM. I took the car to a Toyota repair shop who told me that it needed two catalytic converters and two oxygen sensors which would cost me $2700.

Any ideas of what might cause the engine to vibrate, and whether it has something to do with the catalytic converters and/or oxygen sensors?

I would appreciate any help.

Jacob

[Sark003]

Jacob, replace the motor mounts and trans mount and the vibration issue will go away. The Motor mounts are liquid filled and deteriorate after time and the trans mount will sag to the point that the post will rest on the bottom part of the mount.

Getting to the bottom of the cat issue will be a task for a good tech to determine the cause. It could be a engine management issue also. Be carefull with this issue.

[Jacob]

Sark003,

Thank you for your help. I guess replacing the mounts is not a hard thing to do.

Jacob

[blake918]

It looks like we have the same engine trouble code! You should be dealing with P0420 or P0430 depending on which bank is troublesome, but since they're saying you need 2 cats, you're looking at both banks. Did you ask them if they checked the individual o2 sensors for problems, or did they just read the check engine light? Lexus provides the procedures on how to do so. I'm saying all of this because I'm doubtful that the emissions system all went out at once, but it is entirely possible! That price they gave you is pretty decent-$2700 for two cats and 2 o2 sensors(each cat is about $900, and the O2's are about $140 each).

To your origional question(!): my car runs perfectly smooth(and gives improved fuel econ!!!! I'm thinking my O2 is bad because of the fuel improvement.) with the check engine light on(either the cat or o2), so like sark said, check out the engine/tranny mounts.

Blake

1995 LS400

[Jacob]

blake918,

Would a car pass the emissions test if it had bad catalytic converters? I think not. This makes me a little bit suspicious because the dealer had to run the car through the emissions test before selling it to me.

Jacob

[blake918]

blake918,

Would a car pass the emissions test if it had bad catalytic converters? I think not. This makes me a little bit suspicious because the dealer had to run the car through the emissions test before selling it to me.

Jacob

That's why I said you need to ask the guys at Toyota what they did to diagnose the LS. My guess is they(toyota) plugged the scanner into the car, got either/both P0420 and/or P0430, they pulled out their repair manual and saw that the 2 probable casues associated with the codes Lexus listed are the Cat's and heated O2 sensors, and told you both were defective.*End Toyota service dept. diagnosis* I can post the procedure for testing the o2's if you'd like. Where did you buy the car? Small indep. lot or dealership? I've had Lexus and Toyota dealerships misdiagnose my Lexi a few times, so I take what they tell me with a grain of salt.

[Jacob]

blake918,

I bought the car from a small independent lot.

I’d appreciate it if you can post the procedure for testing the oxygen sensors.

Jacob

[blake918]

I’d appreciate it if you can post the procedure for testing the oxygen sensors.

You just check the resistance between terminals one and two which should be between 11 and 16 ohms at 68deg F.

Edited October 26, 2005 by blake918

[chubyball]

blake918,

Did you get your cats fix from the dealer?

[srgilbert]

I have a 95 with 113K and am pulling the P0420 and P0430 codes. The car passes emissions with flying colors. I'm thinking about using some Catco direct bolt on converters. I believe they are $155 a piece on most of the internet sites. If anyone has tried one let me know.

[blake918]

blake918,

Did you get your cats fix from the dealer?

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My car ended up fixing itself. A few days after the light came on, it went off after I put the car in second gear and went about 70mph. I guess there was something messing with the o2 sensors, and the high rpms blew it out. The cel hasn't come back.

I have a 95 with 113K and am pulling the P0420 and P0430 codes.  The car passes emissions with flying colors.  I'm thinking about using some Catco direct bolt on converters.  I believe they are $155 a piece on most of the internet sites.  If anyone has tried one let me know.

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A 420 and a 430 can also indicate bad o2 sensors not just cat problems. You should check your o2 sensors before replacing the cats. ;)

[SRK]

I'll go out on a limb here to say that any mechanic that says the O2's and the cats need replacing AT THE SAME TIME is no mechanic. One controls the efficiency of the other. The pre cat O2's determine the work load of the cat, and are designed to help the cat swing between reduction and oxidation reactions, while the post cat O2's monitor the efficiency of the cats themselves. As cats aren't part of the OBD system, a post cat O2 code may indicate a cat failure, a precat O2 going slowly out of range, or a faulty post cat O2. That's where a mechanic, and not a "parts hanger" is important.

The cats and the O2 would have become fouled if the car sat on the car lot and was started and idled every day, causing what is called "lot rot". The high speed highway run would have heated everything nice and toasty, and cleaned both the sensor end of all O2's and burned out the cats, allowing them to function properly.

So good job Blake, fixing it yourself, for a few gallons of gas. That's the kind of repair I like too.

[nc211]

I agree with SRK. Jacob, almost every toyota &/or lexus dealership will diagnois a problem with a broad swipe of "replace everything" and not pinpoint the problem. If you go in for a "clunk", they'll recommend upper, lower, strut rods, struts and ball joints to fix it, instead of pinpointing it down to just a bad strut rod. It's just the way they are....salesmen in nature.

[lexluxury]

if you went to a dealership, then their quote is going to be mile high. i goggled the terms 'ls400 and catalytic converters' (something like that anyway) and came up with a web site www.partstrain.com. they sells cat. converters for this car for not v. much. I think they were $300-400. the o2 sensors sold for around 155. do your homework before spending 3 grand on this fix (if indeed that's what needs to be done). you can save a lot by a) finding a lexus-trained indie mechanic who doesn't charge you 100 an hour for labor, as most dealer will, and B) getting your parts at deep discounts. also, the dealers do a 'shotgun' approach to repairs issues, in part to prevent customer complaints.

Hi everybody,

I recently bought a ’96 LS400 with 113K on its odometer. The car sounds good except for two things the check engine light is on, and the engine vibrates around 2000 RPM. I took the car to a Toyota repair shop who told me that it needed two catalytic converters and two oxygen sensors which would cost me $2700.

Any ideas of what might cause the engine to vibrate, and whether it has something to do with the catalytic converters and/or oxygen sensors?

I would appreciate any help.

Jacob

←

[lexluxury]

to my knowledge, i did not insert a smiley in my post. why is there a frickin' smiley smirking in my post? what, is there a smiley spirit living in this forum? a smiley spirit that 'departed' this world in some traumatic event, without resolving his 'issues', so that he has nothing better to do than hang around, causing smiley trouble for the rest of us?

if you went to a dealership, then their quote is going to be mile high. i goggled the terms 'ls400 and catalytic converters' (something like that anyway) and came up with a web site www.partstrain.com.  they sells cat. converters for this car for not v. much. I think they were $300-400.  the o2 sensors sold for around 155.  do your homework before spending 3 grand on this fix (if indeed that's what needs to be done).  you can save a lot by a) finding a lexus-trained indie mechanic who doesn't charge you 100 an hour for labor, as most dealer will, and B) getting your parts at deep discounts.  also, the dealers do a 'shotgun' approach to repairs issues, in part to prevent customer complaints.

Hi everybody,

I recently bought a ’96 LS400 with 113K on its odometer. The car sounds good except for two things the check engine light is on, and the engine vibrates around 2000 RPM. I took the car to a Toyota repair shop who told me that it needed two catalytic converters and two oxygen sensors which would cost me $2700.

Any ideas of what might cause the engine to vibrate, and whether it has something to do with the catalytic converters and/or oxygen sensors?

I would appreciate any help.

Jacob

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[lexluxury]

btw, sometimes people in the parts department at lexus dealerships will refer you to indie mechanics. that's how i found my lexus trained indie guy.

to my knowledge, i did not insert a smiley in my post.  why is there a frickin' smiley smirking in my post? what, is there a smiley spirit living in this forum?  a smiley spirit that 'departed' this world in some traumatic event, without resolving his 'issues', so that he has nothing better to do than hang around, causing smiley trouble for the rest of us?

if you went to a dealership, then their quote is going to be mile high. i goggled the terms 'ls400 and catalytic converters' (something like that anyway) and came up with a web site www.partstrain.com.  they sells cat. converters for this car for not v. much. I think they were $300-400.   the o2 sensors sold for around 155.  do your homework before spending 3 grand on this fix (if indeed that's what needs to be done).  you can save a lot by a) finding a lexus-trained indie mechanic who doesn't charge you 100 an hour for labor, as most dealer will, and B) getting your parts at deep discounts.  also, the dealers do a 'shotgun' approach to repairs issues, in part to prevent customer complaints.

Hi everybody,

I recently bought a ’96 LS400 with 113K on its odometer. The car sounds good except for two things the check engine light is on, and the engine vibrates around 2000 RPM. I took the car to a Toyota repair shop who told me that it needed two catalytic converters and two oxygen sensors which would cost me $2700.

Any ideas of what might cause the engine to vibrate, and whether it has something to do with the catalytic converters and/or oxygen sensors?

I would appreciate any help.

Jacob

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[chubyball]

My car were vibrated @2000rpm for awhile with engine code p0430, indicated the cat problem. It also made weird sucking noise from underneath where the cat were at. Finally, I replaced the cat, the car stopped vibrated, but code p0420 engine code is ON.

I was thinking about swapping the O2 Sensor 1 between bank 1 & 2, see if the new code changed to p0430, if not, I will swap Sensor 2 between bank 1 & 2 again. Before the swap I also think that I will cleaned them good with WD40.

[srgilbert]

blake918,

Did you get your cats fix from the dealer?

←

My car ended up fixing itself. A few days after the light came on, it went off after I put the car in second gear and went about 70mph. I guess there was something messing with the o2 sensors, and the high rpms blew it out. The cel hasn't come back.

I have a 95 with 113K and am pulling the P0420 and P0430 codes.  The car passes emissions with flying colors.  I'm thinking about using some Catco direct bolt on converters.  I believe they are $155 a piece on most of the internet sites.  If anyone has tried one let me know.

←

A 420 and a 430 can also indicate bad o2 sensors not just cat problems. You should check your o2 sensors before replacing the cats. ;)

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I did replace both front sensors and no difference - I'm told that the rears rarely go out. I am also told that the 95 and 96 cats do not last that long - perhaps a generalization. I would swap the rears from bank 0 to 1 however that is a mightly painful exercise.

[chubyball]

Where did you get your Senors? I wonder there are different between dealers and OEM parts? I called Toyota dealer in Carson, CA. They quote me for $110 for each front one, and $120 for rears one. But Autozone quoted me for front @ $90 and $240 for rear. Kind of expensive!!!!!!

[srgilbert]

Where did you get your Senors? I wonder there are different between dealers and OEM parts? I called Toyota dealer in Carson, CA. They quote me for $110 for each front one, and $120 for rears one. But Autozone quoted me for front @ $90 and $240 for rear. Kind of expensive!!!!!!

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Not sure if they still have them but I bought on line - Ebay for Densos - exact plug and play. I believe the fronts were around $75 each.

[chubyball]

srgillbert,

it's a pain in the butt you swap the rears one

[srgilbert]

srgillbert,

it's a pain in the butt you swap the rears one

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To do this you need to pull the carpeting back by the console - correct?