ok, so my CEL came during track day a week or so ago.

It says the O2 sensor (bank 2, passenger side, after cat) is bad.

I finally got around to taking it out to look and the head is broken
off. Uh oh, I look inside the pipe and looks like my random tech
cat broke up and set pieces down stream.

my questions are:

1. I think pieces can be pulled back into the engine so should
I drive it to my shop (about 1 hour away).

2. If so, what damage you do you guys think might have already been done in the recent weeks of driving (and I mean hard).

3. If I replace the cat, do you think pieces might still be stuck in my borla exhaust? do I need to replace that too? is the canister and muffler straight through design?

sigh...
rob

 

aw man, sucks to hear that! I think you should drive it to your shop but go at low low speeds just to make sure the metal will not get sucked in more.

 

I know the SE-R Sentras were sucking some catalyst into their engines and causing damage, but the pre-cat on those things was only a few inches from the exhaust ports. Unless you have some funky cams or something that blow exhaust back upstream, I really don't think you have anything to worry about with the engine.

A few years ago, I took about an RX7 with a buddy and found he had been running with broken cats for over a year. The pieces all turned sideways and stuff so they didn't go farther down the exhaust pipes. I'd pull the pipes to check and the Borlas to shake though.

Good luck on the repair!

 

does anyone know if the borla pipes are straight through exhaust?

in other words, do you think I need to replace the exhaust also or can I hope to clean it out?

Also, can anyone recommend a good Z/G mechanic/shop in
the Fremont to Walnut Creek (east bay) area?

thanks,
rob

 

Mr. Borla posted on here once that a ping pong ball would make it through either pipe just fine. There is a cross over before the muffler though, isn't there?

Now, in the muffler I bet the pipes have lots of little holes in them where tiny chunks could fall into the muffler chamber.

Best of luck to you getting this sorted out.
--
Jeff

 

I remember David Borla mentioning that the true dual exhaust was a straight through design but the pipes crossed over in the muffler. Meaning if you dropped a ping pong ball in at the header on the driver side it would come out the tip on the passenger side.

Edit Jeffw beat me to the punch.

 

n4spd,

same EXACT thing happened to me at CA speedway. ses light kept flickering on/off until it came on solid. car sounded wierd and lost power after that. turns out it was my driver's side RT cat.

i picked up a used set of RT cats (it was a good price and i needed my car running right away) and had them put on at performance nissan. if these cats go also, i'm def. switching to another brand.

the tech at performance told me that the cat material collapsed and did not go downstream to my nismo exhaust.

anyways, hope you get a fix soon. my z is back to normal now.

 

thanks guys!!!

I'm most likely will purchase another brand of high flow cat.
Any suggestions? Links? I've been out of that area for a while
since I thought I had it covered...

rob

 

man thats nasty. Does this happen alot with aftermarket/high flow cats ?

 

wow I wonder if anyone else's RT cats has had these problems? My Ultimate Racing seem fine.

 

This is the first I have heard about blow cats. Maybe it results from the hard track usage. Has anyone blow a cat just a normal street driving? I think the RT cats have a 2 year warranty, so if they fail, you should be able to get them replaced...

 

ya, but take a look at the warranty card...
the amount of things they want in order to "qualify"
makes me just wanna forget it...

so, I ordered the crawford cats instead. once
I get the rt's off, I'm gonna turn them into one
very expensive set of test pipes...

now, does anyone know of a good shop in the EAST BAY?

thanks,
rob

 

Yeah, anyone have this problem with other manu's pipes? I was planning on Crawford but don't feel like wasting $400.

 

Crazy, thats why I never bother getting the RT cats. I have heard horror stories about them blowing out, actually doesn't surprise me. If you want to know the truth RT is one of the "cheaper" brand names for cats. A really good cat that is proven and tested is CARSOUND. You will see this will be happening a lot more often...

 

Carsound makes the Kinetix/Ultimate Racing cats.

 

I have been dealing with RandomTech for years now. I estimate I have sold somewhere close to 600 of their converters. Of those, an estimated dozen have failed. On all occasions but two that i can recall the converters were replaced under warranty. The only time they absolutely will not replace them is when physical damage is done to the comverter body. The ceramic inside can crack on impact and eventually will break. Don't worry about the engine pulling pieces back in. As far as cleaning out the exhaust, the best way toi achieve that is to go on a couple WOT runs and literally blow the pieces out the end.
Contact Clay at Random Tech, (770)554-4242. He is the ONLY person I deal with, very knowledgable and helpful. Also, if the converters are to be replaced, i suggest up-grading to the full metallic converters, the catalyst inside is made of 100% stainless steel and will not crack if impacted. They also flow better than the standard ceramic core converters.

I hope this helps.

 

thanks for the contact number, I may just call him.

but, the Z/G rt cat is of the metallic core kind. It says
it on original box and I've pulled enough pieces from the
o2 port to know.

I've owned other rt cats in past cars and they were fine.
I would not say from this one experience that rt is a bad
or low end company but I do think this one model for the
z/g is a little too weak.

Finally, please do NOT turn this thread into a "bash/defend
rt" thread. I only want advice on how to best fix my current
situation (like some have, thanks)...

rob

 

So if the RT cats are not ceramic then how did it break ?

For clarity, I am not trying to flame RT at all, just wondering since I most likely will be buying some cats from somebody sometime soon and would hate to have to deal with a blown cat.

 

David, I would suggest a Carsound cat from the 3 different companies...Ultimate Racing/Kinetix and I do think Crawford are carsound also.

 

ok, went to my old rx7 performance shop to get the cats replaced
(because they are closer to me) and here's what we found:

1. the following picture shows that the center section of the
metal substrate RT cat broke loose and got lodged right after
the secondary O2 sensor (after taking it out):



2. the following picture shows where the center section used
to be. the sides folded over because of the missing piece...



3. picture of the driver's side cat which had no problem at all.



The mechanic was surprised because the metal substrate cat
should be stronger but I think it's a quality control problem
(I had them for less than 1 year with about 5k miles).

I replaced them with the Crawford high flow cats (looks like
ceramic). So far, I like them. They are much quieter!
I can also feel some of that lost power come back...

best of luck,
rob