A Nissan Sentra Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
63 Posts
Discussion Starter · #1 ·
Howdy. So recently, I’ve gotten the dreaded P0420 code on my 2002 Spec-V Sentra. I’ve had this car since 2015 and I think this is the first time it’s popped up. Ever since I got the code just a few days ago, I’ve been trying to drive it minimally and as close to like a grandma as possible. Since I recently got that code, I feel now would be a good time as any to ask about header swapping to get rid of the infamously fucked up pre-cat. So my questions are:
1. What are some things I should know when installing an aftermarket header?
2. As of 2021, are there any good quality or name brand headers you recommend? From what I’ve read, headers will all boost HP regardless of which you go for so I’m just looking for one that will last. A lot are probably rare now that the platform is old as hell.
3. Are there any that y’all would recommend that would sound decent with a stock exhaust? I’ll probably change it later on but I’d like to keep it stock for now if possible.
4. For anyone that’s specifically had an 02 Spec-V, how temperamental is the ECU when it comes to modding headers and such and is there anything I should look out for? I know some auto adjust for more airflow but I’ve heard these need to be tuned.
Sorry for the long post for anyone that read it. I’ve never really given thought to modding the car until now and if there’s any way I can keep it around for longer, I’d like to. Thanks for reading and I appreciate any and all help! 😁
 

·
Registered
Joined
·
63 Posts
Discussion Starter · #3 ·
Take off the stock header and gut it.
I've honestly considered that. Anything specific I should know about doing that? It's just taking off the header from the block and the exhaust and scraping out the cat lining, no? Have you seen any threads that describe it?
 

·
Registered
Joined
·
406 Posts
find a buddy with a welder, buy a "fake cat" from ebay, cut the OEM one out, weld in the fake, trade the oem cat in for the money it cost you to do what I just said.



to the EPA agent reading this, I am not selling him any of this lol
 

·
Registered
Joined
·
63 Posts
Discussion Starter · #5 ·
find a buddy with a welder, buy a "fake cat" from ebay, cut the OEM one out, weld in the fake, trade the oem cat in for the money it cost you to do what I just said.



to the EPA agent reading this, I am not selling him any of this lol
If a stick welder is fine then I could probably do this. If not then I’m screwed because I doubt anyone I know has a MIG welder. I’m more worried it’s the header pre-cat that’s giving me the P0420 code than it being the exhaust though. The exhaust I can always replace or whatever if the cat on that fails. If the pre-cat fails though, the engine and my first car that lasted me 6 years is dead. I’m scared of that now. And I don’t really know many header manufacturers for the B15 Spec-v that are good quality.
 

·
Registered
Joined
·
406 Posts
in all honesty, aside from slight fitment issues that can be fixed with fairly simple tools, the $100 ones on ebay last a while on a DD car. I had one on my SER for 3-4 years before I went turbo, and never had any issues with it. Just had to expand a hole to make it fit a bit better. Ran a spacer on the second sensor and never had a CEL. Unless your really trying to squeeze every NA horsepower out of the engine, anything more than that isnt going to make much of a difference. idc what people say, a stock SER Spec-v with an insanely expensive header on it and no tune is not going to be any faster than one with a ebay header on it and no tune. And you have an 02, so no tune for you without some serious work lol
 

·
Registered
Joined
·
63 Posts
Discussion Starter · #7 ·
in all honesty, aside from slight fitment issues that can be fixed with fairly simple tools, the $100 ones on ebay last a while on a DD car. I had one on my SER for 3-4 years before I went turbo, and never had any issues with it. Just had to expand a hole to make it fit a bit better. Ran a spacer on the second sensor and never had a CEL. Unless your really trying to squeeze every NA horsepower out of the engine, anything more than that isnt going to make much of a difference. idc what people say, a stock SER Spec-v with an insanely expensive header on it and no tune is not going to be any faster than one with a ebay header on it and no tune. And you have an 02, so no tune for you without some serious work lol
Well, define insanely expensive. Because tbh, if I can get good fitment without minimal tinkering and support for the stock exhaust, that’s worth the price IMO. How hard is it to tune an 02 though? I know they’re finicky and my area of the U.S mainly deals with Subarus (and I don’t think there’s any Nissan tuners in my area anywhere), so I’m kind of out of luck there. Nothing I can do to avoid it running rough if I do go for a header though?
 

·
Registered
Joined
·
757 Posts
Only real good company making a good header is 2j right now, my first header was an eBay one that last me about 2 years, any header with stock exhaust is gonna sound like shift and raspy as hell, my car is also 02 and I didn't get a tune and it was fine, I just re-located the second 02 sensor to behind the second cat, using those 02 sensor spacers is easier tho
 
  • Like
Reactions: Tritton

·
Registered
Joined
·
63 Posts
Discussion Starter · #9 ·
Only real good company making a good header is 2j right now, my first header was an eBay one that last me about 2 years, any header with stock exhaust is gonna sound like shift and raspy as hell, my car is also 02 and I didn't get a tune and it was fine, I just re-located the second 02 sensor to behind the second cat, using those 02 sensor spacers is easier tho
I thought about getting the Medusa one but you gotta chop off the passenger side radiator fan and install the thinner one they sell to get it to fit, no? That's the only reason I've had second thoughts about it. I'd prefer to avoid having to mod like that.
 

·
Registered
Joined
·
406 Posts
Well, define insanely expensive. Because tbh, if I can get good fitment without minimal tinkering and support for the stock exhaust, that’s worth the price IMO. How hard is it to tune an 02 though? I know they’re finicky and my area of the U.S mainly deals with Subarus (and I don’t think there’s any Nissan tuners in my area anywhere), so I’m kind of out of luck there. Nothing I can do to avoid it running rough if I do go for a header though?
You cannot tune an 02-03 car. You have to convert to a newer ecu or do a piggy back, so not really worth the money NA.

The car will run totally fine with a header on it. As mentioned above, it will be a bit raspy on the stock exhaust, unless you have the second cat still in the car, that helps a lot with that.

Where in the US are you?
 

·
Registered
Joined
·
63 Posts
Discussion Starter · #11 ·
You cannot tune an 02-03 car. You have to convert to a newer ecu or do a piggy back, so not really worth the money NA.

The car will run totally fine with a header on it. As mentioned above, it will be a bit raspy on the stock exhaust, unless you have the second cat still in the car, that helps a lot with that.

Where in the US are you?
Specifically Des Moines. I used to live in a suburb outside of Atlanta but that was a long time ago when I was a kid.
 

·
Registered
Joined
·
757 Posts
yes and yes, I’ve had my Nismo now almost as long as I had the car, going on ten years and I still love it as much as the day I bolted it on, for a short header there is no better IMO

I heard the Nismo headers are the best and require no modification, and Magnaflow makes a comple cat-back kit for around 700....
 

·
Registered
Joined
·
63 Posts
Discussion Starter · #14 ·
I heard the Nismo headers are the best and require no modification, and Magnaflow makes a comple cat-back kit for around 700....
There's just one problem though. NISMO stopped making those long ago and I haven't seen or heard of anyone making replicas or reproductions of those headers, with or without the pre-cat in the 6 years I've owned a Spec-V.
 

·
Registered
Joined
·
1,328 Posts
Armonic Performance on fb. He lives and works in Mexico. He worked for B and B, when they were contracted to make original Nismo headers. He makes replicas out of the same material, and even improved on the flows in the primaries. He's been making the reps for about ten years now.
 

Attachments

·
Registered
Joined
·
63 Posts
Discussion Starter · #16 ·
Armonic Performance on fb. He lives and works in Mexico. He worked for B and B, when they were contracted to make original Nismo headers. He makes replicas out of the same material, and even improved on the flows in the primaries. He's been making the reps for about ten years now.
I don’t know how I missed those guys. Any option if I don’t have a Facebook? What exactly is B & B btw?
 

·
Registered
Joined
·
20 Posts
Hows the fitment on newer EBAY exhaust manifolds, no modifications needed...?When you say you ran a spacer for the second sensor what exactly did you mean?
 
1 - 18 of 18 Posts
Top