Car Repair Advice

[Dan Gould]

So the nefarious Check Engine light goes on yesterday, and it just so happens that a couple of weeks ago my wife scrounged up the money to join CarMD.com and purchase the handy-dandy device that takes the code off the computer in the car so we don't have to rely on dishonest mechanics anymore (so long as she can do the repair herself).

Turns out its the catalytic converter - estimated repair cost according to the website a cool thousand bucks.

She's found the part online for about $225 including shipping and is nearly certain its a simple enough job for her to install it.

But my question is this: If a catalytic converter simply insures minimal emissions, is there any harm from leaving it as it is? I don't live in CA so the environmental nazis won't shoot me on sight, but more importantly - what could happen over time to the engine if the converter isn't functioning? Could it effect other systems/parts?

Since she ordered the part its a moot question but I am curious to know.

Thanks, as always, in advance!

[Peter Johnson]

Dan--not sure how old your car is, but if it requires an emission test for registration renewal, it's almost guaranteed to fail if you don't repair it. A bad cat converter can also f*ck with the emissions system, sometimes channeling exhaust back to the engine (if the cat converter has seriously failed, it can break up, rattle around in its housing, and plug up the exhaust/muffler/resonator) and making the car run badly/inefficiently.

Also, make sure that the part she got is vehicle-specific; a "universal" cat converter will often require welding into place (!) whereas a vehicle-specific unit often comes situated within the appropriate exhaust system piping, making it more of a "bolt-in" operation.

Good luck!

[Dan Gould]

Thanks Peter - its a 2000 Honda Civic LX, the part she ordered is specific to the model, and it comes with all hardware needed. (Apparently she has to get some sort of modified wrench to install the sensor without damaging it.) And Florida has no emissions testing.

[JSngry]

If it's jacked, I'd definitely replace it. A bad CC can fail more than emissions tests, as Peter suggests.

[Rooster_Ties]

I vaguely remember a bad CC screwing up part of the rest of my exhaust system on a car I had 15-20 years ago.

Can't remember the details, but I think something broke off and went further downstream - so I probably had to also get the exhaust pipe from the CC back to the muffler replaced (in addition to getting a new muffler, though I think I already needed a new muffler anyway).

[JSngry]

Probably goes without saying, but an exhaust/emissions system does more than just vent out the bad stuff into the air. It also keeps the bad stuff from getting back up into the engine. I have had a car start to run rough & start to stall out completely because of exhaust/emissions problems, specifically a bad CC.

Most of the times, in my experience, the check engine light is usually for some O2 sensor, something you can run with for a while if you really have too. But a CC ain't something to play with.