Hello all.

My 02 Z28 started acting up over the weekend. I thought it had felt kind of sluggish for the past 2 weeks. On Saturday I had to go on a 60 mile drive, and when I was at just about the end of the trip it started to really act up. It wouldn't rev above 4k rpm, and the SES light came on.

When I got to my destination I revved the engine and I could hear rattling in the exhaust. When under load at 4k rpm it sounds like beebees rattling around in a tin can (sometimes).

By the time I got home from my destination (another 60 miles) it wouldn't rev past 2500 rpm in 5th gear.

To me this seemed like a classic case of a failed catalytic converter(s).

My mechanic wasn't convinced and he didn't want to replace them.

He recommended I go to the dealer and have them look at it.

A buddy of mine is a mechanic and he's 99% sure it's a clogged catalytic converter.

The mechanic did give me some info.

The code it threw is R300 - random misfire.

It also seems to have a bad 02 sensor (I believe behind the right cat).

I really don't want to go to the dealer and pay their labor and part rates. I am in the middle of buying a house and have a baby on the way so money is a little tight.

As I'm sure most of you know a direct fit cat costs around $500.

I picked up 2 maremont 38764 catalytic converters for $80/ea from autozone.

I have an appointment to have them installed at a meineke by my house on Thursday morning.

This will literally cut the cost of the repair in half when compared with going to the dealer and paying $500 per converter.

The manager at meineke said he would do the install but that I might get a service engine soon light on the dash since it's an aftermarket converter.

When I asked why he said it might not clean the exhaust as well as an OEM replacement.

So, I feel like I'm taking a risk if I get these maremont converters installed.

Here are my questions:

1 - Does this sound like a classic case of catalytic converter failure to you?

2 - What is your experience with LS1's and aftermarket cats concerning the SES light?

3 - Does maremont make a quality product.

Thanks for reading all this!

Steve

 

A muffler that disintegrates internally will show the same symptoms and make the same sounds. If the Meineke man didn't offer to test your converters for flow and backpressure, you're at the wrong shop (generally true in any event).

 

Thanks for the reply. My car has an slp loudmouth exhaust which I believe has no muffler (resonator).

I also could hear the rattling coming from in front of the resonator.

He did not offer to test them...

Steve

 

Check this out instead. I have a single 3" on my car and it sounds great and looks stock.

http://www.siliconeintakes.com/produ...roducts_id=320

 

If it's got less than 120,000 miles the dealer will replace the converter(s) for free.

 

Listen man...it very well could be clogged converter(s).

BUT...it also coule be a bad 02 sensor(s). You WILL NOT always get an SES light from a failing 02 sensor. I never did. But you will get misfires, sluggish feel, loss of power throughout the rpm range and you'll run rich.

If I were you I'd get 2 new Denso 02 sensors from Bennett Auto....throw them in and see if it fixes it. If it does keep them, if not, return them and tell them they were the wrong ones and get a refund.

.

 

Well I am curious as to where the rattle is comming from. its real easy to find it. get under the car and bang your hand on the exhaust and track it down. Bang on the converter and see if the insides are broken up and clogging. Also remember Converters are meant to last the life of the vehicle, when one goes bad, the engine performance made it go bad, To rich, lean, and coolant contamination. This problem would need to be taken care of before you put the converter on, or else it is going to do the same thing to the new one.