Front Cat. replacement suggestions

[htareen]

i want to replace my front catalytic converter in my 04 ser spec-v. My brother has the exact same make and model and his front cat just came appart and distroyed his engine by sucking in particles. I researched on this and it seems it's not uncommon. So I'm wondering what i should do about it. I've seen that some people have, I think, removed the front cat. and replaced it with a performance header (i think). i might be talking out my *** on that one.

any suggestiongs? i'd really like to keep my spec-v and not trade it in, but i'd also like to do without having to replace my engine.

[PacoBJuarez]

What I'm pretty sure you're referring to here is the infamous pre-cat failure. What you do to prevent this problem happening in your spec-v:

1. Buy a performance racing header. It can be pricey, but it's worth it. It's better than a blown engine. Do some research to find out which ones are the best quality for the value before buying, because it's a big purchase and you might regret not carefully researching it later. I went with DC Sports, but that's not for everyone. I'm sure there are lots of people here who can attest to different brands of headers.2. Put it on. That's it. Putting on a performance header removes the pre-cat and thus the problem. Bingo!

[htareen]

yes, the front-cat failure is definetely the problem my brother had with his spec-v. supposidly the catalytic converter is warrantied to up 80,000 miles so my brother is going to see if nissan will reimburse him for the engine. anyways, do you know if the check engine light will be on if i take out the front-cat and replace it with a performance header? I'm pretty sure the engine computer has a cat check sensor.

I did find a nismo performance header with a cat but i'm not sure how much different the design is from the stock cat.

[nametakennow]

The NISMO one is not prone to breakup.

If you get an aftermarket header without a cat (the common term for this is precat) and move the second O2 sensor back behind the actual cat or use a spark plug defouler to get a "clean" reading you will not get a CEL.

I'd go with a precatless header. The NISMO is ridiculously expensive and doesn't offer much, if any, better performance, so you're better off going with another brand (OBX, DC Sports, and SS Autochrome are all common).

[PacoBJuarez]

Agreed there. The Nismo header is too pricey. There are some OBX ones ghetto cheap on eBay right now. I'd still recommend DC Sports, though.

[nametakennow]

OBX is cheap because it doesn't include a midpipe. If you go OBX, you need to get a Megan Racing midpipe to go with it.

Really any of the 3 brands I mentioned are very good choices in terms of bang-for-your-buck.

[htareen]

do you know if DC Sports makes an '04 spec-v header? i can only find the '02-'03 models.

I do like the SS Autochrome header. Has anyone installed this brand? it's nice that they pre-weld two 0-2 sensor slots into it. and man what a difference in price than the nismo brand.

[nametakennow]

Same engine, same part. The 02-03 will fit any SE-R/Spec V 02-06.

SSAC has upped their quality significantly in the past few years. Because of that, they're definitely an option for B15 2.0 and 2.5 owners. So yes, that'd be a good choice. I'm considering putting an SSAC header on my car in the not too distant future.

[htareen]

I'm surprised nissan hasn't done a recal on the precat yet. An unknowing 2.5L driver would never know the pre-cat failed until the car was pushing out blue smoke like a smurf was on fire.

thanks for all the help, i sure am glad i found this forum.

I think i'm going with the SS Autochrome brand. i'll report back after it's installed and tested.

[nametakennow]

They did issue a recall on the 02-03 precats. They claim they fixed it for '04, but it still happens all the way through 06, including 2.5 Altimas.

Automatic cars are only rarely affected.

[PacoBJuarez]

Nissan band-aided the problem. It's commonly speculated that Nissan really didn't care about fixing the pre-cat problem, and was only focused on future development.

[nametakennow]

More likely is that genuinely developing a better cat and/or rigging up a normal EGR system would have been more costly than replacing the engines on the vehicles that failed was.

[jbarbaresi]

anyone have any opinions on MR catless headers? they are supposedly releasing one soon for the b16's and so far its the only company to be working on anything for our car, just wondering if i should jump on that when it comes out or wait for something else.

[nametakennow]

MR being Megan Racing?

They're probably alright. I'd expect them to copy someone else though, so I find it odd that they're close to being out. Make sure it's stainless. Mild-steel headers will rust, even if they have a coating (it will fall off).

[PacoBJuarez]

Mild-steel headers will rust, even if they have a coating (it will fall off).

It won't always fall off... ceramic-coated can be reliable.
Modified by PacoBJuarez at 8:07 PM 1/14/2008

[gblowtis2000]

Wondering if anybody could clear something up. All the information I have found online about $400 DC Sport header for B15's is that they are a mild steel that is ceramic coated not a stainless. Which makes sense there aren't many cases where you would want to coat a stainless. You guys hear or read different??

[PacoBJuarez]

Nope, they are ceramic-coated. I still prefer the DC Sports brand. I have had no problems with them in the past.

[nametakennow]

I've seen it countless times. I don't trust mild steel with ceramic coatings at all. It's my one beef with Hotshot headers to this date, and why I'd never get one. I suppose I can add DC headers to my list.

First, the coating chips, slowly, yet surely, then chunks of it start to fall off, exposing the mild steel. Then the steel starts to fail at the welds, the weakest point, and that happens to be where the pipes connect to the flange. Next thing I see is a Classified ad for a header that needs some TLC.

Especially with the conditions in Iowa (i.e. ice/snow and salt), Paco, if there's even a little crack in the coating it will rust in a hurry.

It may not happen now, it may not happen in a year or two, but it will happen. Usually it is within a couple years.

Sometimes the steel rusts from the inside out, too. Since the exhaust often has water vapor in it and is, of course, subject to high heat. So it often rusts in spite of the coating.

Get a stainless header and save yourself the headaches.

[PacoBJuarez]

I'll deal with what I've got for now. If that happens in a few years, I'll just replace it or repair it.

[VMPhil]

i was under the impression that DC stopped producing headers for the QR.

Ive running an SSAC for about 2 years now with no problems, its a hotshot knock off.

[PacoBJuarez]

i was under the impression that DC stopped producing headers for the QR.

Nope, they do. go to http://www.autopartswarehouse.com and take a look

[PacoBJuarez]

Ive running an SSAC for about 2 years now with no problems, its a hotshot knock off.

Did you get a midpipe too? I took a look at SSAC, and the one for the QR engine didn't come with a midpipe.