Need advice on removal of catalytic converter

[Pplater]

Hi bros, will greatly appreciate your advice regarding removal of catalytic converter. My engine warning light is being triggered on every 200km or 2 days after i reset ECU to wipe out engine warning light by removing fuses for ECU in fuse box. Recently undergone top overhaul to remove blown gasket and loose piston ring. Ran 1000km thus far since top overhaul. Mechanic advised me engine warning light come on could be due to lubricants used in engine during top overhaul job, causing excess exhaust fumes which overwhelmn catalytic converter. Advised me that if engine warning light symtoms persists after 3 or 4 tankfuls of Techron petrol to wash out lubricants and still engine warning light on, then it must be catalytic converter spoil according to diagnostics test and need to spend 1k+ to fix. Song Yi, authorised stockist for my Hyundai Accent 1.5m quoted me $1450 include air freight from Korea for catalytic converter, so shop is not chopping me. It's parts expensive.

 

My query is rgd removal of catalytic converter, will this cause further problems to smooth and safe running of engine? My understanding is this will "Tong" the exhaust, perhaps drop FC and risk TP fine (which I shall risk), but should solve my engine warning light problem. Mech advised that remove catalytic converter will affect CO2 emissions and may cause Engines Warning Light to keep coming on. Is this true? Am i being sold a con job?

[Caravan]

Normally if you remove the cat, the CEL light will come on as there is a sensor downstream. It won't help your problem at all.

You should go to another workshop for 2nd opinion and if indeed it's the catalytic converter, try to get one from the scrapyard.

[Pplater]

Normally if you remove the cat, the CEL light will come on as there is a sensor downstream. It won't help your problem at all.

You should go to another workshop for 2nd opinion and if indeed it's the catalytic converter, try to get one from the scrapyard.

 

Thanks Caravan. I have considered this option. As it is unlikely regular joe like me can tell whether the scrapyard's cat converter for my model is serviceable, I guess this means buy from them have to take a chance that their cat converter works fine?

 

I'm undecided between get new converter, get from scrapyard or decat. Understand your point rgd CEL light will keep coming on. If I take this option since its the cheapest, I believe engine will run fine as there will be no accumulated pressure in a faulty or clogged converter anymore, and engine should be safe for continued use, correct? Many people decat for power boost, and, this has no mechanical downsides, apart from FC drop right? Appreciate kind bros' advice.

Edited February 9, 2013 by Pplater

[Adilast]

Not sure if u have also check if it is the O2 sensor problem.

 

Many years back I have this same problem... Drove to Komoco they changed the sensor for me.

 

No problem thereafter

[0wnage]

I believe removing the catalytic converter will fail inspection. After which you have to install one back to pass the inspection.

[High_octane]

Basically there is a O2 sensor before the cat and another one after the cat.

How it works is basically calculate the difference between each other to tell if the cat is working or not there at all.

I guess for starters, check the O2 sensor.

 

Those who decat either add in a resistor to the 2nd sensor or adding a spacer (this works by moving the sensor out of the path of exhaust flow to detect less)

If you remove without doing the above, you car will go into "limp" mode and run rich.

 

Overall, if it is really the cat, I suggest getting a used cat from the scrapyards.

Less hassle, less issues with authorities and environmentally friendlier.

 

 

[Pplater]

The mechanic assured me the O2 sensor was fine according to diagnostics test. He used the handheld diagnostic test kit thing. He was sure it was down to the catalytic converter. I had the "Purge Valve" changed, some canister located near the exhaust pipe changed as well. FC at 10.5km/L on 15' Advanti rims I guess the FC is normal. Rims prob a bit heavy and car stock tyres was meant to be 14'. So the FC I think suggests O2 sensor should be normal.

 

Going up Genting tmr. According to his estimates, by this 800km 2 way trip, if the light comes on means can go back to resolve cat converter already. I have clocked 1000km since top overhaul. I have reset ECU twice, and each time it lit up within 2 days. So far it has been 2 days since last reset. Maybe the lubricants used on the engine in the top overhaul job is being combusted away gradually. Makes sense for a progressive delay of CEL being lit up until totally dissapear...

 

Praying very hard it goes away...

Edited February 9, 2013 by Pplater

[Caravan]

Depends on how many years more you want to drive the car. If it's like 4 or 5 years or more, then might as well get a new one. $1k+ for catalytic converter is not that expensive. It's like changing aircon coil + compresssor kind of price.

Removing the cat means the CEL will be permanently on, your fc may drop and you won't know if you have another problem next time (since the light is on permanently). Might as well do nothing if performance is not adversely affected.

If scrap yard can find and the price is much cheaper, then you can take a gamble. Normally cat can last 10 years or more. I still suggest you get a 2nd opinion.

 

You can also buy those US$20+ scan tool and scan it / clear the error code yourself. Then search online for the cause of the error code.

[Pplater]

The car left 2 yr 7 months. My milege will be 100k km due to job. Will see how my malaysia trip goes. Most likely will try decat as cheapest option if light still comes on. Unless I "Xiang Bu Kai" then get new cat Already spend 5k+ change a lot of things to get it road worthy.

Edited February 9, 2013 by Pplater

[Pplater]

Ok. Engine Warning Light no longer lights up after travelling 1000km since top overhaul and change gasket and piston rings. Since the three tries of ECU reset, once by the mechanic and twice by myself, it did not light up for over 1000km, 800km of which was my trip to Genting and back today. FC went up to 13.3km/L. Earlier posting of 10.5km/L was probably a measurement error due to pump attendants' filling up to different levels.

 

In summary, the mechanic's explaination is that lubricants used in top overhaul job causes extra exhaust gases during its combustion. This overwhelms catalytic converter temporarily. Reccomended 3 or 4 tankfuls of Techron petrol to wash out the lubricants and advised not to use SPC 92 petrol which I used for the first tankful immediately after top overhaul job.

 

Info on reseting engine warning light. There are 2 methods. First method is to remove all 4 fuses (for my model) in fuse box. Look at fuse box diagram for ECU fuses. Mech said all 4 must be removed at the same time. Cannot one by one and put back. Second method is to remove battery connection. Note that this method resets your radio station pre-set settings. Both methods will only temporarily reset Engine Warning Light until the trigger for the warning light sets it off again.

 

Posting to bring closure to this thread and thank you all forumers for your inputs and advice offered here . Hope any drivers looking for info on catalytic converter or contemplating decat after top overhaul woes finds the inputs offered here useful

Edited February 12, 2013 by Pplater

[Caravan]

I don't agree with the way you reset your ECU. Are you going to do that everytime you have an error code? What if it is a different error?

 

The proper way is to get a OBD2 scanner which can not only reads error codes but also reset them if you want. Just plug and play, no need messing around with fuse or battery.

 

An e.g. is here: http://www.ebay.com/itm/New-U480-OBD2-OBDI...=item1c2c84a670

 

Cost less than $20. Works on almost all cars.

[Pplater]

I don't agree with the way you reset your ECU. Are you going to do that everytime you have an error code? What if it is a different error?

 

The proper way is to get a OBD2 scanner which can not only reads error codes but also reset them if you want. Just plug and play, no need messing around with fuse or battery.

 

An e.g. is here: http://www.ebay.com/itm/New-U480-OBD2-OBDI...=item1c2c84a670

 

Cost less than $20. Works on almost all cars.

 

Ok. I like the idea. This is rather new to me and I'll check it out. Thanks for the heads up.

[Pplater]

You might want to check up with your local automobile transport division for any legality which might occur if you are going to remove that cat-con. In some countries it is mandatory through regular checkups for proper emissions. For more tips and information on car maintenance visit http://www.automotix.net/autorepair.html

 

I already know its illegal. Fine $700 if i not wrong. This is a minor consideration in my decision making process.

But thank you anyway for ur input and bringing this to the thread.

[Blackyv]

$1.5 is 'cheap' I heard from bil, tan chong quoted him around $10k for his teena ...

[Pplater]

After a week of peace, the CEL light came up again. I had been pumping Ron95 petrol. Still come back to 3 things, Purge Valve, Anti Knock Sensor and CO2 emission fail. Now, I had already changed Anti Knock Sensor and Purge Valve at two different shops, and went JB to get someone else to use the OBD2 Scanner to verify indeed still this 3 things still show up as fault code.

 

If this persists... Guess I will come back to either decat or change new cat coverter.

 

Kinda getting used to CEL light coming up these days. Doesn't feel right if the light doesn't come up

[Joe6057]

Bro, if u decat now & solve problem A, u will have problem B in future, like inspection. car without cat is confirm fail & maybe will kana fine as well. Like other bro mentioned, get a 2nd hand cat as stand by in case stop by TP. Some of TP can tell whether is decat by looking at your tail pipe or by smell. A decat exhaust smell awful. If I'm not wrong, the fine is $500 for decat if kana caught. Also, once decat, the reading will be out for ECU, fc will go up. To solve that, a piggyback is needed to alter the reading for better fc. So end of the day, more $ to spend.. lol

[KaKiLang]

I kenna before many years back, police escort back to Sin Ming for free inspection, $500 or court case if other problem found if you can accept that go ahead.

[Pplater]

Still considering options. Sent to WS today. THey wash the converter. Checked on youtube, really got such thing as use detergent wash cat converter. Ang Moh country got do. Sometimes work, sometimes dun. If cat converter too jia lak then won't work. See how it goes.

 

Decat for a low profile chia like Accent... Tio is sibei sway. Left 2 years car.. Maybe I go decat plus zhng turbo better. Want dun do. Want to do then do all the way. Muahahaha