milellie11

iTrader: (5)

A couple of months ago, i was having this issue with my 02 GS430 with 104,000 miles on it. CEL light, code P0420 stating catalyst insufficient. Dealer says the Cats need to be replaced. I took it to an exhaust guy who felt some air seeping by the gaskets on the Cats, so he put some liquid weld on it.Later, i got a new air filter (old one was clogged) and the CEL light seemed to disappear for about a month and the car drove great. Unfortunately, yesterday, the CEL light was on and the car seemed like it hardly wanted to drive or rev (kinda like the bad gas feel). It runs like crap.

I had ordered some 02 sensors from amazon but sent them back when i thought the car was good. Would bad 02 sensors cause the car to do this and should i waste my time changing them, or should i just try to find some cheap Cats. (cheapest Cats even from Sewell are $992 each!)

Thanks

ThomasGS4

iTrader: (19)

I was having the same issue with an exhaust leak. Haven't received a CEL since it was diagnosed back in December.

milellie11

iTrader: (5)

Did your car have any symptoms? At times did your check engine light keep coming on randomly back and forth and your car would feel like a snail? Did you have a major loss of power at times?

Thanks for your help

Blanco

iTrader: (8)

I have some used ones I'd be willing to part with. I bought them from a salvage company thinking I could put them on my 400. Turns out the bolt patterns are different to the manifolds, so unless I want to cut and weld, I'm looking at a couple of boat anchors.

They came off an 04 430 with 57K miles, and no CELs at the time of removal. The car had been rear ended. I would be willing to sell them to you for what I paid for them $200 for the pair. Let me know if you're interested. I was going to post them to the classifieds, but haven't got around to it yet.

Blanco

iTrader: (8)

I have a leak as well, hence the new cats. My CEL comes and goes periodically, but it never feels like a snail. If you have power loss, it's usually due to clogged cats. Mine aren't clogged, but it almost sounds like a Mustang GT. One of my cats has a bent flange, hence the extra cats I have for sale. I've received several complements on the sound. Several valets have asked what type of exhaust I'm running. I'm too honest to tell them it's anything but a leak. A bit embarrassing sometimes. My wife tells me, "Tell them it's a custom exhaust. How many other GS owners have the same leak"?

CELs with no power loss would probably be O2 sensors. Power loss almost certainly clogged/partially clogged cats.

ThomasGS4

iTrader: (19)

Well, I did have a check engine light, but it would stay on all the time. It turned off by itself once I got it fixed. Naturally you should feel a slight loss in power due to less back pressure of the exhaust.

Rippaflow

iTrader: (4)

I have seeping air on the drivers side after the cat before the secondary o2. Check engine light came on and off for a while, I noticed it stayed on permenantly and now Im going to go get it fixed. Ive had 3 shops try to tell me there was no leak and I needed a cat. You can hear the leak and feel it when you are under the car. I swear people will do anything get that $$$, especially a leak as easy as this one to spot.

GS4_Fiend

iTrader: (22)

Exhaust leak, bad O2 sensors, or bad cat will trigger that code.