Jonathan Gonzalez

Hey guys, I have a p0420 code which is low efficiency in bank 1 cat. i get a small rattle noise when i accelerate at 2k rpm. Now ive dont a bunch of reading on how to fix this issue but there seems to be to many option and im getting confused. Now i have a fed spec 2000 maxima and ive been told to either A. Gut the precat, B. install Ypipe and headers. Now i just bought a warp-speed Ypipe will this fix my p0420 issue if i just replace the ypipe or is ther more to it? also ive read about doing an O2 sim so avoid CEL but some people have told me the O2 sim is only needed for 2002-2003? I need to pass emissions this month to get my tabs and they check codes and smog. All help would be greatly appreciated. thank you for your guys time.

george__

iTrader: (1)

^
Installing a y-pipe won't fix cat problem.

Catalytic converter looks like this (x2)


OBX is (only?) manufacturer left for new

O2 simulator gets rid of the rear O2 simulator service engine light if rear o2 sensors are missing. Get the DUAL OUTPUT one from a site like http://www.o2sim.com

Jonathan Gonzalez

What if I just gut the cat all together? Would that fix the problem? And if I do gut the cat is there anything I need for the O2 sensor?

TurboA32

iTrader: (36)

There's a couple of p0420 tricks you can try but I dont know if it will work for your car but i would gut the cat and try this

https://maxima.org/forums/5th-genera...tallation.html
or this....

george__

iTrader: (1)

The only reason you need to mess with the o2 sensors is because the y-pipes sometimes don't come with the bungs needed. You'll be ifne

maxiiiboy

The reason you are getting the code is that your "watchdog" (i.e., the Rear O2 Sensor) is telling your ECU that "things look dirty back here". Digging one step deeper, there are two possible reasons why the O2 sensor makes this "it looks dirty back here" report:

1. The sensor itself has failed, and is reporting a problem even though there is none.
2. The thing being watched (i.e., the CAT) has indeed failed. Since you hear a bit of rattle at around 2,000 RPM, this might be what's happening with your car.

So, you could try to replace the O2 sensor and eliminate the possibility of condition #1 above. More likely however, your problem is #2. Here, you have the following choices:

1. Replace the CAT converter.
2. Install a Y-pipe, or "gut the headers", or try other solutions in the category of "dump the CAT". With all these solutions, you have to fool the ECU into thinking that the CAT is still there and that it's working just fine; otherwise, the CEL would stay on. The only way to do that - as far as I know - is to install an O2 Simulator.

Finally, you should find out what kind of tests your DMV runs to pass/fail an inspection; I am in California, and dumping my CAT is not an option here, not for me or for anybody else.

Edit: If your CAT is indeed rattling, you may want to get rid of it fast. There are plenty of posts on this forum on how a broken-down CAT can damage your engine.

nestorlugo

iTrader: (11)

Read guys he has FED spec....



Op... the ws ypipe will get rid of your pre cats integrated on the oem y pipe(no guttin required) the main cat however can be replaced by a straight pipe.

Not sure if you need o2 sims but you can pm the dude(screen name) WTF? He recently made some and is willing to make more

Troubleshooting is necessary in order to determine a faulty o2 sensor,

Btw you don't need headers the y pipe bolts up to the stock headers.

WTF?

O2sims don't have them anymore. I can build you any o2 sim you guys need for the rear. Singles and duals.

Jonathan Gonzalez

All of your guys information is greatly appreciated. Like the post above me I am fed spec guys. That's why I was so confused about gutting the pre cats. But anyways for my emission testing they only check for codes using the obd2 port and exhaust smoke.

Jonathan Gonzalez

Another question I had was for whatever reason let's say I needed to gut my main cat. When I go for emissions will they be able to tell? I really don't wanna get hit with a federal fine lol.

TurboA32

iTrader: (36)

The only way they can tell is if you take the cat off and show them lol

nestorlugo

iTrader: (11)

If i were you i'll buy a bluetooth code reader for like $8 and also buy the car gauge pro app to be able to look at live data regarding you o2 sensors ,since you're fed spec you only have( 3 )o2 sensors two primaries on the ypipe and the last one after the main cat .

Install the ws ypipe and remove the main cat for inspection. If they don't do a visual inspection you could also get away with installing a straight pipe instead of the main cat,


It also wouldn't hurt to download the FSM to read up on the p0420 code and how to troubleshoot...

Jonathan Gonzalez

Well here's an update. So I got under the car today and was able to remove all heat shields and bolts to the header. The two 14mm at the back of the ypipe were on tighter then **** and I was unable to get them out. I'll be working on it some more Tuesday I'll keep you guys posted. Again thank you for all of your guys help I appreciate it. When I hit the lotto it's boosted maximas for everyone!!!! Lmao

maxiiiboy

Well, that depends on how they do the emissions test in your state. You need to ask around. I am in California, and on my last three tests, my car was subjected to the following tests:
- Check for CEL light and any pending codes (max 1 pending code allowed),
- Visual inspection (for O2 simulators and other "forbidden" modifications), etc.),
- Analysis of my exhaust fumes; done by a machine, and the machine reports the results directly to the DMV, so that the operator can't intervene (hence, can't be bribed).
Good luck!

Itz Shak

Mmm... Boosted maxima..