Cat converters

[Shawn_hollen]

I am thinking about taking off my cat converters and putting straight pipes in place of them. A couple reasons I'm thinking about it. First reason is because they need replaced. Second reason I seen my buddy's Monte Carlo throwing flames out the tail pipes. He did it by taking off the cats and useing strIght pipes. And mashing the gas and letting off gas peadle quickly. It dumps a lot of gas into exhaust it cause it to throw flames. I plan on putting converters back on but thought it be cool for my q45 to throw flames for a short while. Any way my question is. Has anyone done there q with straight pipe with no converters. If so how much louder did it make it?

[Q451990]

Without other modifications, you won't get flames out of you Q's exhaust. That much fuel being dumped into the exhaust system would have melted your cats for sure.

[Aquaholic21]

You could rig up a fuel injector and a BBQ ignitor if you want to shoot flames.

[BadQ45t]

Back in the day taking the Cats off was a great way to get more power, but newer cars not so much. If they are shot and you don't have to pass a smog test in Indiana then what the heck, do it. They used to make these little parts called "Test Tubes" which were essentially made to replace the cat converter to "test" if it was bad..which was the easy way to get rid of the old style POS cat converters. If you don't need to pass smog that might be the easy way out, if you do then start shopping for replacement converters.

[elwesso]

Only bummer is that you'll have to fool the ECU to not throw a CEL somehow (various ways to do it) because the downstream o2 sensors are going to be looking air readings with the cats there...

No emissions test in Indiana, but you'll be hard pressed to find any muffler shop that will do it...

[Shawn_hollen]

I already cut the cats off and just used strait pipes in replace of them my buddy is going to bypass the ecu this weekend not sure how he said he can do it so I'll let u know how he does when finished

[EdBwoy]

Wait, how many cats does the y33 have? If you have 2 per bank like most Nissan v8s I've dealt with, then the CEL and/or ECU interference might not apply depending on whether its the primary or secondary cat eliminated.
Was there an o2 sensor downstream of the cats you cut off?
Got pictures of the underside before/after?

[Shawn_hollen]

Just 2 cats but 4 02 sensors

[BCC93QT]

I am unfamiliar with indiana restrictions but keep in mind even without emissions testing they still look for the "required" exhaust and some shops might look for the 4 cats when inspected. Even more states call for unmodified exhaust. I know up here in Massachusetts they atleast need to visible check for the cats. I punched mine "pre cats" long ago on my g50 and in the winter time you can sometimes get some strong odors in which will never pass exhaust. But 375k+ if you have original cats they are more likely to admire it rather than complain

[Shawn_hollen]

They never check for them just if u get pulled over and ur car is loud they might check it. I do all my exhaust work and all work on my car so no one will see only me.

[Shawn_hollen]

I'd like to get rid of the o2 sensors if possible they r exspensive and a pain. I'll look into that next