clogged catalytic converter

luke713 · February 21, 2007

hey guys...i have an '01 silverado 2wd 1500 with the 5.3l...i was getting a check engine light which would bring up the code that cyl 3 was misfiring...wasn't a surprise because the engine is skipping...i changed the plugs and wires and even the injector...same problem occurred...i brought it to the dealer and they put it on their computer and said that the converter was clogged...they want to charge me $1000 to change the converter, because it comes with a new "Y"-pipe and some of the exhaust, thats how they sell it...they went on to saying that other converters wouldn't work...have you all ever heard of something like only the converter from the dealer working...seems fishy to me.

thanks,

luke

GasHog369 · February 22, 2007

it may be covered under warranty!! Im almost certain that catalytic converters are covered for 7-8 years or 80,000 miles?? might be able to google yoour state and see...

if not, go to advance auto or some similar auto store, and get a aftermarket cat for around 100 bux and pay a mechanic to put it in...

dealers are for warranty work, after the warranty stick with a mechanic you trust...

ShakinLM7 · February 22, 2007

You wire them in place of your o2 sensors and they trick your computer into thinking everything is fine. I'm hoping it is the rear o2's that are causing the code otherwise I'll have to figure something else out. I've read several places its ok to use the simulators on the rears but the front o2's are used by the computer to adjust air/fuel ratio and what not. I'll let you know how it works either way I just ordered them tonight so it will be a few days at the least.

ShakinLM7 · February 21, 2007

I spent 60 bucks on a flexible drill extension, a 2 inch wire brush and a 1 3/4 inch spade bit and hollowed mine out! I have to buy O2 simulators because it is throwing a code but the truck runs fine! I believe it helped add a little low end power and lowered the tone of my duels a little . If you have to have semitones tests on your truck I don't know if it would pass with them being hollowed out but unless you break out a thermometer you cant tell they are hollow just by looking at them. I know there are a ton of guys out there that run aftermarket high flow cats on new GM trucks and still pass emissions tests.

luke713 · February 22, 2007

yeah i read up on the simulators...the job of the rear O2 sensors is to test the emissions and only send a code if the emissions are wrong or the plug malfunctions...the job of the front sensor is to adjust the air/fuel ratio...other than simulators, you can reprogram the chip/computer to bypass the rear sensor...either method will only pass emissions test if they connect to computer to inspect...if they use the sniffer at the tailpipe, you fail...but i have called a muffler shop, and they said that the dealership is doing their job, and that aftermarket parts will work fine...thanks for the help and knowledge...you all have helped plenty