Removing catalytic converter

janciani · May 25, 2016

Before you get all judgy I didn't want to remove them let me explain

Today I went to a exhaust repair shop, my truck (2010 Silvetado LT 4x4 Crew Cab - 5.3L) was doing some weird noise that I though it was related with the exhaust, I was thinking it was a leak. They checked and told me that my filters were obstructed and because of that my truck wasn't accelerating very good and could cause damage to the manifold gasket and even worst. So they tell me that they will remove them and weld a straight pipe so the air can flow normally and I can gain all the power back (keep in mind that at that moment I hadn't realize those "filters" were the catalytic converters) after that I decided to install a muffler to improve the sound a little bit. So they finished all the work I was happy with they sound, after leaving the shop the check engine light turned on and I hear the same sound coming from the manifold. I went back and they told I need to replace the exhaust manifold gasket wich I think is okay because my truck is on 150k mile range.

So here is my real question: Is my check engine light on because of the gasket? because of the CC? or both?

Keep in mind I'm from Venezuela, nobody here care about emissions and about fuel (I can fill my empty tank with 0.60$) my problem is with the CEL and I'm ordering a set of manifold gasket to replace them.

Thank you for your time and help.

anumber1 · May 26, 2016

So, yeah... if the catalytic convertors were removed, you are going to have a CEL lit. Probably a "cat low efficiency" or "sensor2" code.

The system checks cat efficency. If they have been removed, your gonna get a light lit.

David_ERD · May 26, 2016

You will have that light on because you don't have cats before the O2 sensor. I did long tube headers and had the same thing happen to me. I would recommend getting it custom tuned by someone using HP tuners, you can turn off that code in the tune and the light will not be on. They can also adjust your air fuel ratio which will help. Not too sure that it's ok to be driving around with no cats when it's untuned.

janciani · May 26, 2016

So, yeah... if the catalytic convertors were removed, you are going to have a CEL lit. Probably a "cat low efficiency" or "sensor2" code.

The system checks cat efficency. If they have been removed, your gonna get a light lit.

You will have that light on because you don't have cats before the O2 sensor. I did long tube headers and had the same thing happen to me. I would recommend getting it custom tuned by someone using HP tuners, you can turn off that code in the tune and the light will not be on. They can also adjust your air fuel ratio which will help. Not too sure that it's ok to be driving around with no cats when it's untuned.

Ok they told me they would install them back on, but is it true that they can get obstructed? or will I be better installing them back on?

I like the idea about tuning my truck but with the economy in my country paying $300 for that is a really high expense and I have other things to buy that are more important right now, anyway thank you for the idea and your time to answer my question.

muddkatt · May 26, 2016

Yes, they can clog up. or break apart and cause then to be obstructed. On my 2001, the cat broke loose on the inside and sounded like a rod knocking. I took it off, broke all the honeycomb apart using a long metal rod, then reinstalled it. Its been like that for about 150,000 miles.

janciani · May 27, 2016

Yes, they can clog up. or break apart and cause then to be obstructed. On my 2001, the cat broke loose on the inside and sounded like a rod knocking. I took it off, broke all the honeycomb apart using a long metal rod, then reinstalled it. Its been like that for about 150,000 miles.

This is what I needed to know, can I brake all the components inside the cat and leave it empty? To reinstall them and turn the CEL off

muddkatt · May 27, 2016

Yes you can break the guts out of it and reinstall it, but the CEL will stay on. Someone told me that you can remove the O2 sensor and add a spark plug non fouler ( http://www.summitracing.com/parts/rnb-42002?seid=srese1&gclid=Cj0KEQjwvZq6BRC9kfq2zKfQ_94BEiQAOeUVC5bu1ZhajztTrrgjy1B1MFTlG03LcdaXmIVTmKN_-iAaAr5d8P8HAQ) and it will keep the CEL off. I don't know that to be true or false.

nekkidhillbilly · June 1, 2016

Yes you can break the guts out of it and reinstall it, but the CEL will stay on. Someone told me that you can remove the O2 sensor and add a spark plug non fouler ( http://www.summitracing.com/parts/rnb-42002?seid=srese1&gclid=Cj0KEQjwvZq6BRC9kfq2zKfQ_94BEiQAOeUVC5bu1ZhajztTrrgjy1B1MFTlG03LcdaXmIVTmKN_-iAaAr5d8P8HAQ) and it will keep the CEL off. I don't know that to be true or false.

that works or they make 02 adapters that are basically the same thing but already drilled out like the foulers need to be. I bought some off amazon for 5 bucks I think.