I was wondering if having no cats at all on my max is bad for the engine? Theres no emissons testing where I live. I didn't think I would have a problem with no cats, but maybe I missing something. By the way my car is a daily driver if that matters.

 

Its not harmfull on the engine at all, the smell your going to get in the summer kinda sucks. Smells kinda like oil is being burned by the engine in my Maxima. I haven't had a cat on my car for a long time- all 3 are gone.

 

No wonder why the worl suffers from alot of Lung related diseases(sp?)

 

dude the gain isnt worth it.. think about the future generations.. where i live i sit in traffic for 40 min.. and with thousands of cars running at nearly idle for 40 min with no cats. my city would be BLACK with smoke.. dont remove them. just take out your back seat and you will take the same amount of weight off..

plus they give a little back pressure so you get that nice tourque feel

 

drop the front two with a y pipe, then get a high flow, if your poor go with gutting the back cat, it will throw a code though, witch may put your car into a "safe mode" condition, it does it on my thunderbird, MPG goes to the crapper and you go to a safe timing, witch is like next to nothing, so if you do it maybe find some MIL's, or a tune of some kind to turn the rear o2s off

the loss of backpressure may not be enough to make your car less torque, it just depends on the rest of the exhaust, but if it where me id do a high flow cat and delete the front cats and get a high flow middle, one, works as good as anything

 

Most aftermarket cats don't last too long, Catco and Random Technology cats usually last 2 years Max and then the honeycomb starts to fall apart. 90% of 01 cars are Cali spec and all 02-03 are like Cali spec cars. These cars do NOT have a 02 sensor behind the rear main cat, so if you remove that sucka it will NOT throw a check engine light for inop cats. I thought bout installing one cat back on- as it kinda smells bad in the summer, but I don't wanna be repleacing it in a year or 2 again.

 

o mines a federal spec 00 so i didnt know how the other ones worked, and my birds rear o2s are after the front cats so yeah, the CEL is on

 

I'm all for extra power but removing cats is selfish and wrong. The environment and the health of future generations is more important than a few extra horses. Just because you can do something doesn't mean you should. It's only a matter of time before every area has smog testing so you might as well get used to it now and work around it. Remember, more smog = less fresh O2 for the engine = less performance. We were not put here to abuse earth and leave a **** hole for our kids. Please think long term and instead of the normal American way of immediate gratification.

Just my 2 cents.

 

Just curious, how the hell you get them by EPA emmissions tests?

p.s. kind of miss the old disturbing sig...

 

the cat being removed, once the car is warm, should still pass emissions given your car is in decent tune. I have no cats, i'll never go back. The smell is cheap gas we're exposed to, and if you live in FLA like some of you do here, half of the counties have no emissions because the pop density isn't enough to produce a measurable detrimental effect on the environment, you gulf coasters, like you mentioned in tampa, you guys are screwed with air no matter what we burn. According to nissan, 00 came in fed, or cali/nlev(CT is an NLEV state). All 01's are cali/nlev. The differences, albeit exhaust-wise is dramatic, horsepower differences are negligible, as desertpearl demonstrated. Cat free is the way to be, your engine , as any, will operate best under natural conditions, and as an air pump, it doesn't want restrictions, so uncap it, release the beast.

 

Um, no.

Not at all.

 

cat's burn off excessive fuel left after ignition. If you remove it, any excessive fuel (which, if there wasn't, your car would be running too lean. I know, I blew a 1" hole through a piston once doing exactly that) would go straight into the emmisions equipment and you wouldn't pass. I think your confusion lies in the fact that the 5th gens have two cats: one on the header and the main cat. You can remove the one on the header, but the main cat has to stay to pass.

 

Catalytic converters do not "burn" anything. They create a chemical reaction when exhaust gas passes through them, that reduces emissions. If there was unburned excessive fuel passing straight thru your exhaust system, there would be something very wrong with your car, and it would be running SO rich that I doubt it would even start.

5th generation Maxima's have 3 catalytic converters. One for each cylinder bank (in the Y-pipe), and one further downstream in the exhaust system.

 

thank-you turbo g, i was waiting for someone else to step in and explain that, so that i would not be attacked by the eco-friendly.