Hi new to the forum. I have a 2001 nissan maxima 20th anniversary edition 3.0l n/a i want to kno if i can delete all 3 catilyic converters without having too much issues? Has anyone ever done it? Id like to have it straight piped if possible. Any advice would be nice. Thanks.🙂

 

Please don't. If you want a more aggressive exhaust, fine change it. But leave the primary cat in place at a minimum.
Hopefully where you live you will fail emission testing/inspection if you were to remove the primary cat.

 

My '02 has gutted precats (necessary on the 5.5 gen due to a ****ty design) and a Cattman high flow main cat. You can definitely smell the car when it's running in the garage or something, but it would be worse without the main cat in place. I've had no issues since gutting the pre-cats and it didn't really add any exhaust noise. Best bet on your 2001 is to just get a y-pipe and catback if you want more noise.

 

I think pre-cats won't be a huge issue. The options are to gut them or install a y-pipe. Removing the main cat will cause a check engine light so you'll have to do a workaround.

I do agree with Wizard, please leave in the main cat at least. I know a lot of car guys bash emissions regulations. But if you've ever experienced the air quality in a country with no emissions regulations, you'll be thankful just about every car here has catalytic convertors.


Edit---
Also, if you're looking for a "louder" exhaust. Be sure you are the kind of guy that can bare the noise if this is a daily driver. A few years ago I thought it would be cool to have a cat back exhaust on my 99 SE. During hard acceleration it sounded great, but idling/cruising it would have a "brrrrrrr" noise that became unbearable and I put the factory muffler back in after a few weeks. I was in my early 20's so not quite an old fart yet, LOL.

 

Do you have 3 or 4 O2 sensors?
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Any catalytic converter with an O2 sensor directly after it will cause a CEL if said cat is removed. There are work arounds such as sims or spacers.

 

sssshhhhh. Don't encourage him. LOL

 

A few follow questions about gutting the precats.
1. Does gutting precats set off the CES light?
2. Did you see any power or responsiveness gains?
3. How to gut? After removal, are you just hammering and chiselling out the crap?

 

1. Does gutting precats set off the CES light? Yes since the downstream o2 sensors will detect a value outside of normal specs. You need a spacer to pull the sensor slightly out of the exhaust stream to get it to read less to prevent a trigger. There also also Sims you can wire up to trick the sensor into a correct value.
2. Did you see any power or responsiveness gains? Slight gains and a slightly deeper exhaust note on acceleration.
3. How to gut? After removal, are you just hammering and chiseling out the crap? That's what it looked like when I watched someone do it to mine.

 

18" spade drill bit and a powered drill and about 1 hours, and a mask.

its harder getting the precats off the car to gut, i bought used junkyard ones that looked like titantic relics. gutted them and had a shop install them as "customer supplied parts", i have the sim installed as well, fingers crossed, in hindsight i would prolly do a bung spacer.

tone is slightly deeper, not too much at all, i hate super loud exhausts and its not bad whatsover.

i have warpspeed y-pipe and stainless main post cat. and oem ish b-pipe muffler (axleback)

 

How much did it cost you to do that?

 

It was so many years ago, but I want to say it was $200 or less. I provided the o2 spacers.

 

it costed me $50 for the sim $50 for the used pre cats and about $600 in labor , it took the shop about 8-10 hours to get the original 15 year old precats off the car and install the new ones.

 

I hung around when the guy did mine and it took about 2-3 hours. There is nothing around where it was done (willets point Queens) so I just stayed in the area. I remember they had a chore chiseling out one of the two precats.

The guy was a member of the NYC Maxima forums and his dad had a garage in Willets Point. Pulling in there was like a 3rd world country.

 

Have any of you guys or have known someone that has tried the aftermarket Stillen Axle Back exhaust system?

https://stillen.com/products/2019-ni...-system-504403

 

if you run without cats you will need O2 sensor spacers to get rid of the CEL light. I have gutted cats on my 02 and it didn't get louder at all just deeper I think. here is a sound clip I posted on youtube. from my experience exhaust only gets louder when you get a loud muffler.

 

Do full headers or a y-pipe. The bank 1 primary cat on our cars is impossible to gut the easy way. Youd have to cut it open and then reweld the hole you made. Ive been through this debacle a while ago and finally got my headers on. O2 sensor spacers are needed for the sensor 2’s or else youll get a cel. The weight savings and power gains with the headers are unbeatable. It is a very large task, but its doable with the right tools and patience

 

Can you please send a link what kind and where you purchased your headers?

 

You're right on a 3.0 gutting pre cats isn't worth it. The 3.5 crowd recommends gutting since their cats and Y are separate and they blindly chime in without realizing the differences.

 

Any of the ebay headers for a 3.5 altima works. You
might have a hard time finding a set though. I got mine through thomas purdue jr on facebook. Id send him a pm on facebook and ask if hes still making them during the summer. I was lucky enough to score a set he had laying around. Also
Ill add, you need to have thomas make them for you. He mods them and the y pipe to fit the 3.0. So either way, get in touch with him. Best of luck

 

2000 Max. SE/ 5 spd. manual / Long CAI / Cattman Y & B pipes / 3 cats deleted / car runs & sounds great, but you smells rich in enclosed space of open garage.