Test Pipes? What to Know....
 

I am considering replacing my Cats with test pipes, assuming I will get a few extra ponies (I know it won't be drastic, but 5 or 10 would be nice) when I lose the restriction on the exhaust.

I have a 2019 Nismo and I have questions. I am looking at something like this: They claim a "built in O2 CEL (Check Engine Light) fix. What in the heck is that??? The O2 sensor is certainly going to detect something outside of the normal range and set off the CEL, right? I don't want to have to clear the error codes everytime I drive the car! How can this be? Should I go for resonated or not? How much, what difference results??? What is the difference? Any other suggestions, recommendations?

Thanks guys!!!!

Go with a HFC. I would since all the EPA crap has started.

Do yourself a favor and invest in quality HFC’s. I had test pipes for more years than I care to admit and I would reck of gasoline people would tell me LOL. I recently installed the AAM HFC’s I really like them and the exhaust note.

I will eventually get a tune, but if I go with HFCs, must I get a tune immediately? Or are HFCs no different to the system as the stock cats???

Hfc's
 

You don't need a tune immediately after installing them. But you'll want a tune to get the most benefit from your intake/exhaust mods. just make sure that whoever is doing your cats doesn't use power tools/impact drills to remove and install. This WILL kill your 02 sensors. I just went through this.

If you still decide you'd like to do a cat delete instead of HFC's, then go with Motordyne ART pipes. I have the same model car as you, except it's a 2015. Keep your Nismo muffler. Also consider the Garageline X and Mid-Pipe combo. Nice rumble under the floor, but no drone or unwanted noise, and you can carry on a quiet conversation. With just those mods, and no tune, I dynoed 312hp/269tq.

Be advised, however, if you do the Garageline and ART pipes, you can't cut in HFC's. I tried to have a mechanic do this, but the joints, and undercarriage and frame just didn't allow for it. The only way to do all this with HFC's is with a complete Fast Intentions system.

I have Art Pipes and Motordyne catback on a 2017 Nismo. No drone at all, and volume is totally controllable. I've been tuned on UPREV for over 2 years with no problems.

I've used the Berk Test pipe for years and only replaced it when I went TT. You will need a tune and have your Tuner disable the O2 Sensor. Without a tune you will need to keep resetting the CEL or live with it on. BUT since your in CA, they do make things called "mini cat" 02 sensors that should work, they worked for me to pass emissions in NJ.

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html <-I used this one.
https://prosportgauges.com/products/...l-fix-straight