DpG $h0rTeE

iTrader: (3)

Smog certificate due on 9/20 so I go down to my local Arco station to get my car smogged. My mods are frankencar intake, budget Y, OBX catback. I had switched back to my stock intake the day before as to pass visual inspection. I drove around for about 30 min to get the engine warm and the Cat Converter hot as well. For the test, i wait about 15 min and find out it failed.
On the results, the "NO (PPM)" max is 437 and i got a 751. - this was at 15MPH (new dyno Smog)
For the 25MPH test the max is 724 and I got a 311 which is pass. anyone know what these numbers mean? I also paid 60 bucks for them to diagnose why it failed and they tell me its my Cat Converter. Ive heard people pass all the time with stock CAT and aftermarket y-pipe just as long as the CAT is hot. Any suggestions on to what to do?? Deadline is commin up soon and im started to stress. The SMOG tech told me to replace my cat and it should pass.

DpG $h0rTeE

iTrader: (3)

im also speculating that one of my O2 sensors is bad (got CEL couple months ago) and thats causing the cat not to function properly. Anyone have some feedback?? i dont wanna end up spending another $100 for a new CAT only to find out that it wasnt the problem.

Nismo87SE

Your car is a 98 and they put it on the emission dyno? Aren't all 96+ cars supposed to get a OBD-II test and all the cars older than 95 get put on the dyno?

ivelweyz

Yeah that's what they do here in Illinois. My car just goes for the OBD2 test and nothing else, no visual check no nothing...

DpG $h0rTeE

iTrader: (3)

I think Cali has one of the most strictest emission laws in the US. Take a look at the brown smog layer over Los Angeles and I guess you see why.

ANyways, anyone thing I should replace the CAt like the guy said or one of the O2 sensors? this is what i think the problem is according to this: http://www.car-sound.com/05converter/05reason.htm

DpG $h0rTeE

iTrader: (3)

bump

Anyone?

Kevin Wong

I'm in Southern California and I was in the same boat as you. I failed the smog check, had it diagnosed and low and behold...it was the cat. I was quoted for $800 for an OEM Nissan Cat. I was in despair, when I suddenly realized that I had an RT Cat sitting in my garage that I bought 2 years ago from Nick Stam, but just never installed. I popped it on and the next day I passed (but just barely).

Now I'm wondering how my stock cat went bad after only 65K miles. I suspect the Knock sensor and O2's. I'm going to be changing those out really soon. As for the cat, I found a bunch of stock alternatives. They are as low as $135 for an OEM-equivalent online. Good luck, I can relate to your frustration.

ivelweyz

No aftermarket cat is even close to the quality of OEM. The "filtering" efficiency is 2x that of any aftermarket cat, still $840 is not worth for a cat...

Kevin Wong

As I stated above, I failed with a stock cat and passed with the RT. My understanding is that its not the RT that passed me, but rather a new cat passed me. My stock cat had fouled out, I suspect the car was running out of tune for some time because of the knock and/or O2 sensors. But if you type "OEM Maxima catalytic" You'll find a bunch of OEM-equivalent cats for as low as $135 and as high as $400.

techie

I may be wrong, but I thought your cat should be covered under warranty for 8 years or 80,000 miles. Reason I say this is my other car is a 98 Grand Cherokee and getting a new Cat put on for free (under warranty) right now because I'm under 8/80, over original warranty but under 8/80. I was told all original catalytic converters have to be covered for that long because it is a governmentally mandated requirement. I'm not sure how it is with Nissan, but I'd check out the warranty if it is the cat.

NYCe MaXiMa

iTrader: (9)

cant he knock sensor have an effect on emissions?

I BARELY passed this year, came 0.07 short to the limit in one of the three fields they test in NY.


I don't have any O2 sensor codes but the car does have a lot of miles and I had the knock sensor code pop up once but it only came on with another code.. it doesn't come on individually by itself.

JAY25

iTrader: (38)

Look heres the deal from me to you, I failed emissions like it was no tomorrow about 5 months ago, fine, no problem, I dont know what readings you got but I was on the rich side but the car was not boosted, that means too much fuel, I went got the best brake cleaner removed the O2 sensors sprayed them blow dried them, replaced the sparkplugs and voala total cost $11.00. Went back and sliced the high numbers by 75%. This car was a nissan and it was NA just like yours. I dont know if it would apply to this car as well. 98 vehicles they hook up a computer to and they dont run you on the rollers but I guess your stuck thats why on the boosted car I have Fl plates vice Ga plates.

-=PK=-Maxima

i'm in the same position as you right now. my muffler shop guy said i need a new cat or stock y which will be costing anywhere from 800-1,000 bucks!! no freakin clue as what to do. i was just thinking about paying someone off to "fix it" for me but the muffler shop guy said that if i've already taken the test once and failed they wont be able to "fix it" for me. if you guys have any suggestions or any smog shops in southern cali that do such things please let us know. thanks

1FSTMAX

iTrader: (29)

I just had a smog check recently here in SoCal, my car passed with flying colors. All I have is a catback and hybrid intake. In my case my car was put on the rollers, and they hooked up the smog computer to check for any codes.

DpG $h0rTeE

iTrader: (3)

Thanks for the help guys. Im starting to lean towards buying a new cat. Today, i just got back from 2 local muffler shops with the intentions of replacing my cat and they tell me that I need to have a special "OBD-II" certified cat or something like that and that installing those universal/aftermarket ones is too risky of I were to get caught. IS THIS TRUE?? Are the Cats that they sell online (warpspeed, RT, carsound) all "OBD-II" or were the mufflers guys just tryin to BS me into buying a more expensive converter?? Need to know ASAP cause this weekend I will be busy and wont be able to work on the car and SMOG cert. due next SAT already

Also, how hard is it to change spark plugs and remove the o2 sensors? (any special tools needed?) I might do what Jay25 did and save myself $$

njmaxseltd

iTrader: (19)

Don't be so fast to buy a new Cat. Change your plugs and clean your throttle body. I bet you'll pass smog easily once you do that. If your Cat or an o2 was bad you'd definately fail smog at all speeds, not just 15MPH or idle. I'd spend the money on plugs and a can of TB cleaner first.

DpG $h0rTeE

iTrader: (3)

yea im planning to clean my o2 sensors and change spark plugs. Any idea about the OBD-II thing ??

tattoo

Also get an engine top end cleaner and use it.take one of your vaccum lines on t-body and let the engine suck it in at like 2-3k rpm.this will dislodge any deposits from combustion chamber.btw your car failed for nox,or oxides of nitrogen.make sure your car isnt running hot,or lean as nox is a result of high combustion temps.good luck

DpG $h0rTeE

iTrader: (3)

What do you mean by running hot?? I drove the car around vigorously for about 30 min. to get that Cat converter warmed up so it can function properly. Was i not supposed to do that? And will bad/dirty O2 sensors be a cause for my car running lean??
Any ideas if i should order a new CAT? need to know soon because itll take couple days to ship and i only have about a week til deadline. Thanks

-Nick

DpG $h0rTeE

iTrader: (3)

bump.......

-=PK=-Maxima

just go pay someone off and stop stressing yourself. or go barrow someone's cat use it for the smog test......pass....and give it back to them