SO i finally went to get an estimate on how much it will cost me to replace some components on my exhaust system today. I was a bit shocked at an estimate of over $1400. I have a 2002 I35, The cat near the firewall, and the y-pipe, the main cat, remove the rear exhaust manifold, pipe before the muffler. All those items they say need to be replaced, I looked under the car myself while it was in the air, most of the parts dont look as bad as i thought. If i use their expensive parts its $700 just for the rear pre cat, and the y-pipe. No way lol ill buy my own parts, its mainly just rusted where the pre cats bolt onto the y-pipe. Labor was est at $600.

 

That's crazy.. try another muffler shop

 

Is your CEL on? Why are they looking to replace the pre cat if theres nothing wrong with it. If you just need the b=pipe and muffler that's really cheap to replace. I purchased both for less than $250.00 and had a shop put it on for $75.00



This is the set up I got..

 

Kool nice set up man, But the thing is those parts are not even rusted on my car/ at least not yet. Everything from the main cat back seems to be in good shape. Yes the Check engine light came on for P0420 a few weeks ago, rear pre- cat, So im assuming it is bad, but I erased the code, has not come back yet but that was a ridulous price to replace just a few parts. The y-pipe looks to be in ok shape but looks like the leak is in the flex pipe.

 

You can get the whole rear section from the main cat back for $150. You can pick up a main cat for $50 and I'm sure the b pipe from the pre cats to the main cat isn't that expensive. No way would I pay $1400

 

I had to replace my precat last year. I had the P0430 code and had to cat replaced.

 

O2 spacer in the meantime...

 

Yeah That is crazy, like im getting a perfomance exhaust or something. I think ive seen a y-pipe for just under $150. Then the guy tells me the car only has 2 cats lol. Yes I am just going to get the part myself, and then go to another shop and see what their labor will be.

 

^ This is the way to go. Just put the non-foulers in and be down with it.
$10 compared to $700+.

 

You can get both precats for a hair under $300. I will be doing that to my daughters 03..
I am replacing my entire exhaust. I'm going with headers. I have the main cat replaced and then a cat back system. Mine is starting to look really bad

 

sounds great, im gonna go ahead and start buying the parts online, as long as i know exactly what needs replacing now. Most of the parts are not as expensive as this guy is trying to sell me. Ive seen walker y-pipes, and precats for way less than i was quoted lol.

I see a pace setter rear pre cat near the firewall part number 201102 for $134 on amazon, is that a good replacement? I see it does not come with the studs built in though.




under the car




y-pipe

anyone ever tried the bosal y-pipe part number 6710-05166995 its $165 on parts geek.com, if so does it come with the 02 sensor hole like the stock y-pipe?

 

Well I will be buying a new car back system for mine. This happened this morning

 

ouch!!! did it just fall off like that? Hopefully mine doesnt fall off until im ready to replace that part.

 

Didn't fall off but it was just hanging there banging around. Pipe just rusted apart. I'm going to end up going full stainless. I ordered the stainless Megan racing cat back yesterday. I have a stainless main cat already. Now I just need is the obx stainless headers. It's going to have to wait a little though. Money is alway tight this time of year

 

For the love of FSM, do not replace the cats.

 

why not replace them? I just dont want a loud car and for it to run right without the 02 trick. I plan to get a new y-pipe bosal part #800-069 from parts geek, replace the main cat, and the rear pre-cat.

 

It's a waste of money (apply the cash elsewhere), gutting them doesn't make the car louder with stock catback, and secondary O2s are unrelated to engine operation (plus defoulers are cheap).

Front precat falls apart faster than rear, just a FYI. Replacing one won't save the engine.

 

Well if it wont make the car louder by gutting them, then im all for it. Just keep getting a code for po420, leak in the flex pipe, so def going to replace that, Ill have to see what a shop will charge me to gut the precats. THanks for that advice. Car does not seem to be burning oil at this point, not going to talk too fast though.

 

They'll only do it if they really like you since it's a felony. Or perhaps they can give them to you and you gut them lol. May be able to find a set that are gutted by asking in Classifieds.
The front falls out, usually. It's the rear that's a pain.

 

ok ill look into either option man, just trying to take care of these repairs before i make a long trip.

So im either going to go with just replacing the whole y-pipe with a bosal brand, ive heard that the warp-speed brand is not a good fit, and possibly just replace the rear pre cat and main cat, but just inspect both and see what my options are, or just get a new flex pipe welded onto the oe y-pipe.

 

A real man installs headers

Kind of pointless since you don't seem to care about power or noise (WHY NOT)
But is a solution that fixes everything. And I think it would be the same or cheaper than new cats/Y. Although, I guess there's possible fitment issues still with OBX.

 

Dont get me wrong, i do love the deeper tone of the 3.5 and the power, but is bosal a good brand of y-pipe? Im all for making extra power, but want to keep the noise to a minimum, and who knows maybe in the future ill install headers, but just for now I want to make sure i get it running in top shape. But will i sacrifice low end power with a bosal y-pipe? will it make more noise? Ive heard people saying they deleted both pre cats, just to hear the car make a pop sound on deceleration, is that tru?

 

I don't see why bosal wouldn't be fine. Nothing you do with a stock catback is going to reduce low end, imo. Small tubing equals high velocity.

I've had headers/gutted cat with stock catback and know a car with all three cats gutted and stock catback. The only thing it did soundwise was give a slight bit of throatiness, but still very quiet. Think G35 exhaust. Power increase was definitely noticeable. I bet it makes a lot more under the curve.

If your Y doesn't have deep rust and only the flex is bad, then just have a new flex spliced in and save even more money.

 

I think there may be some confusion of noises when compared to which cats are deleted. The pre-cats are in the Y-pipe. Gut them. Any increase in noise due to gutting those alone should be minimal, because the main cat, the big one, is still there further down the chain.

The OTHER CAT, the main cat under the car, now the deletion of that one can significantly change the sound of the car. Leave that one as is.

I'm willing to bet that the pop sound on deceleration came from a guy who had gutted the main cat as well as the pre cats, and perhaps said that he gutted the cats, leaving some ambiguity in his statement/observation.

 

I don't recall any popping and there's no way it could be very loud with a honkin', chambered muffler. And does a soft "poof poof" count as popping? It's hard enough to get my headers, test pipe and 3" cat back to make loud pops at 7k rpm.

 

yeah u have a good point man, I like the g35 and the fx35 exhaust notes, they are sweet! Yeah the y-pipe looks like it can go a little longer, so im just gonna get that flex section put in, get that 3.5 punch back.

 

That poof poof is the pop pop......muffled I bet the chambered muffler reduced what would have been a snap, crackle and pop on lifting the throttle, to a poof poof. Had it been a straight through muffler.......I wouldn't want to be behind you when you take your foot off the gas

 

I'm always out terrorizing the city

 

I believe you are correct, I removed the main cat on my 2nd gen maxima, yes it got louder, but the power was great. I will see what condition the main cat is in once i take it to another exhaust shop, but definetly not going to remove/delete that one.

 

Maxinout - Were you able to source this part. Found a universal on Amazon 2.5" X 8" X 12", not sure of the dimensions required.

 

no i havent found one yet, i thought that most exhaust shops would carry it or at least be able to weld in a peice of pipe for the broken flex section.

 

Good luck if you think they'll have one. They'll stick one that's 2" on it b/c that's what most seem to carry.

If you go to something like speed shop or one known to do custom exhausts, then you'll be fine. But if you're talking someplace ultra cheap like midas or w/e, they don't have crap.

 

yeah i see what you are saying man, this is my next project on this car, and im kinda starting to like the sporty sound lol, as im getting used to it, but def going to get this taken care of.

 

now i have the 420 and 430 codes smh.

 

Time for those cats to go

 

I've gutted my cats(yes all 3 of them) and as far as sound goes it's a tap louder but not bad at all-but the engine pull is way harder compared to before,and I do have the 02 extenders no CEL,but I may just put the main cat back on(new one) just so I'll be somewhat legal-lol

 

definetly time for those things to go, only one ill probaly replace is the main cat.

 

Im eagerly ready to get rid of my cats. Going with an obx header so I can have a full stainless exhaust system. My megan cat back hasn't shipped yet. Uhg....

Now does anyone know if you need a programmer to get air fuel ratios right after a header install to see any significant power gains?

 

There's no point to that. If you want to keep it, then just clean it. Think saving money, not wasting it on useless parts
Hippies think cats help the air. They don't, really. It's a waste of precious metals.

15 ocean ships pollute the same as all the cars in the world (SOx wise). One big ship will pollute as much as 50 million cars. Emissions testing is a scam. Notice how regulations don't apply to stuff that generates lots of revenue, is owned by corporations or is just really dirty in general.

Hell, people have passed sniffer tests with no cats on well running VQs (I imagine a lot of good motors can).

 

Yeah im going to another exhaust shop on saturday to get another estimate on the work that needs to be done, rusted bolts on the y-pipe, pre cat, flex section, and also see if i can get them to remove the pre- cats and i just get rid of the insides, and they reinstall them. But how do you clean the main cat?? lol