Neo7241

Hey all,
Recently had my service engine lamp come on. Decided it was also time for an oil change, so took it to my local Chevy dealer. Engine light diagnosis came up as....
"Code p0420 traced to bank catalytic converter failure." Dude stated something that wasn't a priority to get done, but was a "must do" so light will stay active until fixed. And the repair cost quoted at $1685.
I know there is a fair amount of dealer shenanigans out there. I am just curious if anyone has had to have this repair recently (or not so recently, I guess). I have a local repair shop that I take my truck to for alingment, tires, and other stuff. Think it's a fair bet they would be cheaper? Or is this pretty much a dealer repair. It's for my '05 Vette, and not under warranty.
BTW, I had a C4 pimp me at a light, so....had to teach him a lesson. Wasn't even close. But, as I looked at my dash, I noticed the engine light was no longer hot. I know the cat still needs repair, just curious.
Paul

BadAV

At that price you are well on your way to buying long tube headers with catted pipes. Or, if your car is a stick, replacing with a complete Z06 exhaust system from manifolds to mufflers. There were a couple for sale for around $750 in the forum recently. Or just have the converter cut out and a new one welded in for a lot less money.

BlindSpot

Some thoughts. Besides agreeing with BADAV (good time to mod the exhaust), if you're just looking to repair, and assuming the issue was diagnosed correctly, there are stock C6 exhaust components used all over the place. And for practically nothing. Check Ebay, Parts FS on CF and CL. The Z06 is a good upgrade choice too and 1/3rd the price of new LTs.

BTW, a P420 could be a bad rear O2 sensor too, just a coin toss whether the Cat failed or the sensor. Dealers have a bad habit of not wasting time diagnosing properly and just throwing parts at a problem. They might have quoted you both replacements (cat and O2 sensor so they're sure to get the problem as well as the bigger labor job.

If you're confident in your skills, there is a cheapo way of testing the O2 sensor. Just switch the left rear O2 sensor (p0420) with the right rear O2 sensor. If you now generate a P0430, then the sensor was bad all along and the cat is probably OK.

Unreal

In addition, certain years had a TSB to update ECU for cat codes, as they tripped too easily. I would confirm your car has the proper ECU updates and it is a known false code.

hippy

What others have said about stock parts availability is true. My FULL C6 LS2 exhaust ended up at the recycler due to no interest in buying it, that was manifolds to mufflers. I currently have another full set that is worth about the same which I believe was 5 or 7 dollars from the junk man.

schizcat

Just get a replacement set from here .... either stock or upgrade (trust, you will like the upgrade if you go long tubes). Look around for reputable Corvette specialty shops in your area or a performance shop. They will do a better job a diagnosing the issue than the dealer. If you decided to stay stock, they would probably be a lot cheaper too. They may have an extra O2 sensor or cat\header laying around that they will let go on the cheap.

Neo7241

Wow...I need to do some research. My Vette history is 2 C3's both 350 small block, and easy mods. I have only had this '05 for 2 months now, and I suppose I "assumed" everything was going to be so much more expensive. I certainly like the idea of the Z06 system. So I got the $1,800 put aside for the repair, but thought it best to ask some elders on here. Sure glad I did. Thanks!

schizcat

One other thing I would like to mention is that if you have the means to work on your own car, you can do a header swap yourself. It can be done on jack stands. A little tedious but its pretty straight forward. You can save yourself a little coin on labor this way. You will also have to account for changing the plugs, wires and gaskets (not necessary but with the age on the car, may be needed).