I have the typical carbon problem that all these 4.3L, 6 cylinder vortechBlazers have, so it is pretty often that my egr and O2 sensors go crazy, and it runs like crap for a while. Well, I think my Cat. converter is finally fried as a result, and I want to simply cut the bastard off, and replace with pipe. I have heard that there is a way to fake it or trick the O2 sensor that is typically downstream of the cat once it is removed so it will run smooth and help fix my problem. I think I am going to have to replace the O2 sensors as it is, and would love to not pay for a cat. Any suggestions? Also, if anyone knows of easy or cheap ways to help fix the carob problem, that would be great

 

Lets start by you telling us what you have here so we don't have to run around all over the place to hope to find one post where you state it. Please put your vehicle information atleast in your profile, better yet, in your signature and attach it to all of your posts. This will help out greatly. By backwalking your posts, I found that you have a '95 Blazer. 2 O2 sensors, 1 upstream for fuel managment and 1 downstream for catalyst monitoring.

Now, in the US, this it is illegal to eliminate the catalytic converter. Why not buy a universal 2.5 in/out converter and have it installed. Depending on the source of the cat, $60 + installation and you're done. Heck, some pipes/clamps and a hacksaw and you're done in your driveway.

There are no O2 sims for our trucks. So you'd have to attempt to make one of the others available for off-road use work for the rear O2 sensor. You cannot sim the front sensor as these are used for fuel delivery. So what exactly have you gained.

Are you even getting any codes specifically stating something about the rear most O2 sensor or cat converter efficiency? If not, then I doubt your converter is plugged up. You'd know it if it were. Most exhaust shops can run a back pressure test to determine how 'clogged' a converter is.

The carbon is a by-product of combustion. You just have to deal with it. Some engines create more than others. If you can, use a top-tier gasoline source and it should help reduce the amount of carbon resulting from combustion. Put EGR, TB, and upper intake cleaning on a regular maintenance schedule and stick to it. Make sure that your O2 sensor is working properly as to not over/under fuel the engine.

 

should have my truck details attached as my signature now. I am getting codes that the O2 sensors are bad, and it is definately running rich as a result. It isn't that old of a cat., but it is allready clogged it seems after a couple years with the O2 problem etc. I suppose I could just put a new one on, and replace the O2 sensors, but I just need to figure out a solution as It is dumping way too much fuel, and runs poorly fairly often. Once I get new sensors, cat. etc., what should be a good route to help prevent it other than cleaning as you decribed?

 

What codes is it giving? If you have a bad upstream sensor, I would ignore any of the codes for the downstream until you get the upstream fixed. Just clear and see if it comes back after you affect repairs up front.

The front O2 sensor is the only one that has anything to do with fuel delivery. The catalytic converter doesn't have a say in the matter. I would recommend that you replace the front O2 sensor with a genuine AC Delco sensor and see how things go from there. I also recommend that you atleast remove and clean the spark plugs as dirty/faulty plugs can ruin O2 sensors just the same as a faulty O2 sensor can ruin a set of plugs.

And I wouldn't just up and change the catalytic converter on a wim... You really should have it properly diagnosed before even thinking about it.

 

sounds good. I will check out the plugs and O2 sensor, and see what happens. I just need to get it back to square one so it runs properly..