Cat Converters

[IndyRon]

:chairshot:

I think my catalyc converters are shot! I can not afford the replacement coast of 2400.00 Right now. I was wondering if anyone knows what would happen if I was to knock out the middle of the cats? we dont have emmisions control here

BUT I know that there are o2 sensors behind and in front of my cats!

how will all this effect?

This is just temp until I can get the new cats!

I am having the same problem as another post where I have absolutly NO power to get up to speed and my gas milage is 7-8 miles a gallon

[tansupplyman]

You should probably ask Lextreme about this since he has installed turbo's/superchargers, etc and more than likely discarded the cats.

http://www.lextreme.com/

If I didn't have emissions cks, there is NO WAY that I[if you] would pay $2400. to get new cats back on the car.

You do need to find out what the 2 rear O2's will do with the cats not there. that is what Lextreme probably has 1st hand knowledge of; not to infer that no one else does.

[SKperformance]

Get a motor vac ,it is a high pressure fuel cleanign system that always cleans everything perfectly including the catsd for about 100

[1995ls400]

where can you get on of those motor vacs done at... Jiffy Lube, Lexus Dealer.

I think my catalytic converter is going bad also, and I ain't gonna pay $2400. thanks

1995ls400

[tansupplyman]

motorvac test report FYI(I know nothing about it):

http://www.theautochannel.com/mania/repair/motorvac.html

Don't forget about BG44K---I use that about every 10k-15k.

[SKperformance]

not a bad article at all.it explains it much better than i could have in a couple of words.

[SRK]

My advice is to ignore the Motorvac treatment. Bunch of hype. All manufacturers are required to warranty the emission control system to 50k in North America, otherwise they can't sell their cars here. Consequently they are designed to work in the long term, and the idea that a little bit of valve deposit ruins their careful planning and design is ridiculous.

These cars have pre and post catalytic convertor O2 sensors. The purpose of the post cat O2 is to confirm that the cat is doing its job. When it detects a swing in the oxygen content, it will trip a code for that particular cat, indicating it is faulty. If the O2 is removed, the engine will run fine, but the code will be tripped continually. The pre-cat O2 has the major function of determining fuel trim in closed loop (warm) operation. It must be present for the engine to run, or the fuel system will go into limp home or the equivalent, which is normally very rich.

If no code has been tripped, then the converters are fine. Cleaning the cats is quite easy, and most manufacturers allow a rich mixture during wide open throttle, and the system goes into open loop at that point as well. This heats up the convertor and allows it to self clean. If your engine has not been driven hard lately, and has been puttering around town for a while, a few full throttle runs down the highway will do more to clean the cats, and the fuel injectors, and the valves, and the pistons, than all the Motorvac silliness combined.

[SKperformance]

Everyones a critic.

but if you have never had one then you have no basis for fact other than "i would think"?

To me thelink to the site sounds like propaganda. But all in all it is true as that is what it does and it works.

A plugged cat still works just not as efficently.

And no a few runs on the highway will not remove more carbon deposits than a motorvac.

Like i siad before if you haven't had one tried it and driven the car before and after then you have nothing to base it on but

"i guess"

[VBdenny]

Maybe I missed something but what were the symptoms you are getting that make you think your converters are bad? I only ever had one go bad and that was on a 75 Plymouth Gran Fury that had msotly regular gas (with lead) put in it. The car went slower and slower and the power steadily decreased until you had to floor it to go 30.

This all happened within 150 miles on one day. You will know very soon if they are bad. When I changed the oil the other day, I was looking at the exhaust system. Rather strange configuration. The manifold pipes go into two catalytic converters, then into one muffler, then two two pipes back to two more mufflers, then two resinators. With all the componets, I wasn't exactly sure what was what.

My car is a 1990 with about a buck-forty on the odo. Exhaust system still looks perfect.

[1995ls400]

Well guys,

I think it is both fact and fiction, however a clean fuel/exhaust system is better than a dirty one. I had the error code (P042) come up on my car last month, and the diagnosis was to replace the 02 sensors. I tried to convince the lexus dealer to reset the code, but they said you couldn't reset that code. So, I spent the money and had all four of them replaced and, just this weekend my check engine light came back on and I got the same error code, so apparently is was not my 02 sensors. The dealership also said that my cat converter was going bad.

Like you said, I have never had one of those go out on any car I have owned. So I figured it has to be something else. and a dirty fuel system which leads to a dirty exhuast system sounded good to me. So I decided to try the motorvac system.

I called all around town for hours trying to find a repair place that uses the motorvac system. Most of the dealerships, national known shops didn't use it. but And I finally found one. Other places wanted to charge me the same price for dumping a few bottles in my gas tank and oil. But to me, it just sounds better to have a machine do it for me.

anyway, after I had my car cleaned, I noticed an instant improvement. My car is really driving better. the gas pedal and take off feels fluid again. also the error code went off. I will see if my gas mileage changes on my next big trip. I would say that for $100 it is defintely worth it. I might even say me $2000 for a new cat converter. only time will tell. I will keep you all posted.

1995ls400

[SRK]

Well guys,

I think it is both fact and fiction, however a clean fuel/exhaust system is better than a dirty one. I had the error code (P042) come up on my car last month, and the diagnosis was to replace the 02 sensors. I tried to convince the lexus dealer to reset the code, but they said you couldn't reset that code.

What concerns me is that there is a separate code for each O2 sensor, and the chances of all four needing replacement, suddenly, at the same time, are slim to none. Also, obviously the code can be "cleared" which is what you meant by saying "reset", and they should have known that too. Their diagnosis was faulty or less than ethical.

Keeping the fuel system clean is a good idea, and for me a bottle of Techron does it once a year.

[VBdenny]

Typical Lexus dealer. Throw money (yours) at the problem, and see if it works. I imagine you were fairly steamed when the check engine light came back on.

I usually add a bottle of Valvoline Complete Fuel System Cleaner every other oil change (about twice a year). Seems to keep everything running fine. I still haven't tried the BK44 or whatever it is, reviews on that have been good.

[SKperformance]

The dealer knows they can clear a code but it won't change anything but put it back on in a few minutes or minutes .Also they have to cover there !Removed! , if one goes the others usually follow .So rather than you come back next week they tell you all.

I am glad to hear there is someone else who actually has tried it and it worked just as it is supposed to.

Regular fuel treatments work fine but it is the difference bettween washing your car with a 40psi garden hose compared to a 2000 psi power washer. The is a difference even if it didn't have any chemicals added.

Sometimes simple does work,as parts go bad for few reasons under engineering , damage and dirt.

I hope your problems are over,make sure you keep an eye on your gas milage i would love to hear about it.

I also forgot to mention there is another machine called terra clean that does it, usually about the same or less price but the same quality.

[SRK]

The dealer knows they can clear a code but it won't change anything but put it back on in a few minutes or minutes .Also they have to cover there !Removed! , if one goes the others usually follow .So rather than you come back next week they tell you all.

Quite frankly, and respectfully, this is not true. The fact that one O2 sensor fails does not indicate that the others are soon to follow. Lexus, like other manufacturers, dedicates a specific trouble code to each of the four O2's and only the one that has failed needs to be replaced. The others can be scanned to prove that their operation is correct. They may last the life of the car, or need replacing next week, but their continued operation is not dependant on the others. ANY mechanic who tells you otherwise is being untruthfull. And at the price Lexus demands for their O2's the last thing you want to do is replace them unneccessarily. A pal of mine's LS400 had it left front O2 fail last year. One O2 replaced, code cleared, engine has run perfectly since.

About the only thing that would damage all of them is leaded fuel, or another chemical introduced into the fuel.......now what were we orginally talking about....?

[SKperformance]

could have ,would have, might have.

This is the dealer they replace as much as they can ,we all know that but they also stand behind there overglorified work. That is what you pay for.

Clearing a code does nothing but blind you to the fact that something went wrong. It may have stopped but it still was there. The ecu also monitors the sensors for tripping and resets the cel light after 3 full runs of the engine.

So what is the point of disconnecting the ecu?

Never mind i don't want an answer.

This is after the point. We can continue a debate over the might have beens if the cel comes back with the same indication,otherwise this really is pointless.

[JPI]

I don't know which dealer you prefer to, there are lexus tech outhere that are still clueless. To test the a/f sensor and the cat converter is very simple if you have the right tool. You can also check the a/f sensor by using a volt meter and ohms it out. Not all tech are the same and please don't bash them. I never see 2 sensor goes out at the same time. Know how to test them is the key. And don't assume cleaning out the injectors will clear the check engine light.

JPI

[SKperformance]

assuming cleaning the engine would work ,never

more than likely depending on the situation ,

but either way you lose nothing as you gain economy and performance back.

[SRK]

I don't know which dealer you prefer to, there are lexus tech outhere that are still clueless. To test the a/f sensor and the cat converter is very simple if you have the right tool. You can also check the a/f sensor by using a volt meter and ohms it out. Not all tech are the same and please don't bash them. I never see 2 sensor goes out at the same time. Know how to test them is the key. And don't assume cleaning out the injectors will clear the check engine light.

JPI

Well said JPI. Obviously you believe in accurate diagnosis, and I admire that. It is what I strive for myself.

[SKperformance]

Well guys,

I think it is both fact and fiction, however a clean fuel/exhaust system is better than a dirty one. I had the error code (P042) come up on my car last month, and the diagnosis was to replace the 02 sensors. I tried to convince the lexus dealer to reset the code, but they said you couldn't reset that code. So, I spent the money and had all four of them replaced and, just this weekend my check engine light came back on and I got the same error code, so apparently is was not my 02 sensors. The dealership also said that my cat converter was going bad.

Like you said, I have never had one of those go out on any car I have owned. So I figured it has to be something else. and a dirty fuel system which leads to a dirty exhuast system sounded good to me. So I decided to try the motorvac system.

I called all around town for hours trying to find a repair place that uses the motorvac system. Most of the dealerships, national known shops didn't use it. but And I finally found one. Other places wanted to charge me the same price for dumping a few bottles in my gas tank and oil. But to me, it just sounds better to have a machine do it for me.

anyway, after I had my car cleaned, I noticed an instant improvement. My car is really driving better. the gas pedal and take off feels fluid again. also the error code went off. I will see if my gas mileage changes on my next big trip. I would say that for $100 it is defintely worth it. I might even say me $2000 for a new cat converter. only time will tell. I will keep you all posted.

1995ls400

so how is the gas milage and the codes?