Cat Converter

[LTJGWorth]

How do you know when you catalytic converter plugs? Will it throw the sensor and show a light? The reason I ask is because I want to take the cat off my truck. Damn thing is stealing my horsepower!

[moparmike70]

Catalytic converters rarely "plug" up unless your engine isn't running properly (ie. running very rich or burning oil). All the newer vehicles have an O2 sensor to monitor the converters performance so if there was a problem the check engine light would come on. The easiest way to tell if there is a problem with the converter is to take out an upstream O2 and start the engine. If there is a problem with the converter you will notice a big difference in power when you rev the engine. This may set off your check engine light but it is the easiest way to check it without a back pressure gauge.

[LTJGWorth]

Thanks. My truck runs almost perfect. No check engine lights of anything like that. I was just curious. I figure it would throw the O2 sensor and turn on the light. I do want to take this converter off. How do you go around the O2 sensor?

[BleedDodge]

Remove converter. Put new pipes in place. Tap hole in one of the pipes so you can stick the sensor in. You're done.

[LTJGWorth]

Nice!

[hundahunta]

you need to install a resistor in place of the o2 sensor...If you remove the cat and install straight pipes, you may get a converter catalyist efficiency code...It would be the same as the coverter not working... The pre o2 sensor voltage will mirror the post sensor and set a code...

[BleedDodge]

That's where you take the bulb out from the "Check Engine" light area.

[LTJGWorth]

Well lets see... does it not work if you tap the pipe and put the sensor in? Do I have to use a resistor? I'm not taking the bulb out of my check engine light. I still need that.

[GreenlandMopar]

Ahh yea taking the bulb outta the check engine light trick hahaha i have done that oh to many times.. umm the do make low restriction cats that you can put on instead of by passing it and worring about the O2 sensor...

[LTJGWorth]

I want no cat period. Even "low restriction" cats steal hp. I'll probably just figure it out myself. I'm pretty good with that stuff anyway.

[BleedDodge]

All you need is the first sensor. The second one you can totally unplug and hang up in your closet. My grandfather's truck has only the first sensor tapped into the driver's side cylinder bank side, near where the cat used to be, and it's been more than 2 years now that he's had it like this, and still no codes yet. Gas mileage is good too. That truck barks!

[LTJGWorth]

Nice.

[TrailLeadr]

This will depend on how your cat is constructed, but here's the basic idea.

Take the cat off the vehicle.
Get yourself a grinder with a cutoff wheel, and open 'er up.
Make a slice across the top of the cat (so it can't be seen)
peel the outer skin back, and then with extreme care, RIP IT's GUTS OUT!
Replace the chambers within the cat with a straight pipe connecting both ends of the cat.
Fold the outer skin of the cat back down, and it you have a welder,
give it a couple tacks, otherwise use a steel exhaust strap, and a couple sheet metal screws to tie it back up.

Reinstall the cat back in it's original location.

This will keep the local inspection stations from rejecting your vehicle come inspection time. (provided that your state inspects....some don't)
and sitll get you the straight through exhaust that you really want!

[LTJGWorth]

Nope, no inspections in good ol' Kentucky. Hell, the inspectors probably don't even have cats on their cars. I've got a 84 GMC Jimmy without cats. I ripped them off when my exaust rusted out and I put dual exaust in it's place (without the cats).

[BleedDodge]

I don't blame you, I love my straightpipes too.